Actinide Elements and their Compounds with other Elements. Part 2

425 Pages·1993·14.289 MB·English

by  R. Troc, W. Suski (auth.), H.P.J. Wijn (eds.)

Ref. p. 71 3.4.1 An-main group element: introduction 1
3 Magnetic properties of actinide elements and compounds
3.1 Actinide elements
3.2 Compoundso f actinide elementsw ith 3 d elements
3.3 Compoundso f actinide elementsw ith 4 d or 5 d elements
SeeS ubvolume1 11/19fl
3.4 Compounds of actinide elements with main group elements
3.4.1 Introduction
It is obvious that the formation of actinide compounds will usually lead to a pronounced increase
in the separation of magnetic atoms and thus to a decrease in the f-f wavefunction overlap.
Nevertheless, the self-consistent-field calculations for free ions show that the 5f electrons (sees ect. 3.1)
have a substantially larger spatial extent than the 4f electrons, and thus one can expect complexity in
their behaviour also in chemical compounds. Therefore, it is of great importance to examine the
dependence of the magnetic properties of the actinide compounds in relation to the An-An
interatomic spacing. Indeed, more than 20 years ago Hill pointed out that most of the known actinide
compounds could be divided into nonmagnetic (often super-conducting) and magnetic ones consider-
ing only the An-An distance, the major factor which governs the 5f electron localization process.T he
critical distances, with severalj ustified exceptions, are x0.350.325 and 0.34 nm for the U, Np and Pu
compounds, respectively (Fig. I) However, more recently it has turned out that also the crystal
structure and the kind of the other component (ligand) seriously influence the entire behaviour of the
actinide compounds [85Kl]. This is mainly due to the so-called hybridization between the 5f and
conduction electrons. Thus this hybridization being an electron transfer between the f-states of the
actinide atoms and the conduction states (formed mainly by the ligand valence electrons) is the reason
of the broadening of the localized 5f level into a very narrow Sf-band. As a result a large 5f electron
density at energy E,, appears near the Fermi energy E,.
The actinide elements form numerous semimetallic and intermetallic compounds. The first
comprehensive description of their crystal structure was given by Lam et al. in [74Fl]. The bulk
magnetic and related properties of above compounds were reported in the chapters by Lam and
Aldred as well as by Brodsky et al. in [74Fl] and by Fournier and TroC in [85F2]. There is also a
book devoted to the magnetic behaviour of the actinide semimetallic and intermetallic compounds by
P. Erdos and J.M. Robinson [83El]. The main physical properties of the intermetallic actinide
compounds have recently been compiled by Sechovsky and Havela [SSSl].
The actinide intermetallics studied up-to-date can roughly be divided into several groups; one
group with rather small An-An distances, but not only that group, shows an exchange-enhanced
paramagnetism (EEP) being weakly temperature-dependent (WTDP) or completely temperature-
independent (TIP), a second group exhibits a spin fluctuation (SF) behaviour, like, e.g., UAl,, USn,,
etc, or an itinerant-electron magnetism (IEM).
Land&-Bdmstein
New Series lllj19f2
2 3.4.1 An-main group element: introduction [Ref. p. 7
Usually the compounds with a large An-An distance have clearly localized magnetic behaviour,
but also this is not a general rule. To the last group belong the so-called “heavy-fermion” systems
(HFS), which have anomalously high values of the electronic specific heat coefficient y, being
temperature-dependent. Usually the value extrapolated to T = 0 K is given in the literature, y(0).
At present the HF systems are under most extensive examination and for this reason they are
discussed at the beginning of this introduction, whereas the other materials will be described
according to the main stoichiometry in which they subsequently occur in subsects.3 .4.2 and 3.4.3.
140
K
0
0.30 0.35 0.60 0x5 0.50 0.65n m 0.70
Fig. I. Magnetic ordering temperatures, T, and TN, as a
function of the An-An distance for numerous metallic
actinide systems. 0: LM ferromagnets; A: IM ferro-
magnets; 0: LM antiferromagnets; A: IM antiferro-
magnets; Cl: paramagnets; n : spin fluctuation systems.
(LM: local moment, IM: itinerant moment)
Ref. p. 71 3.4.1 An-main group element: introduction 3
3.4.1.1 Heavy-fermion systems
In recent years intensive investigations are being focused on the few uranium compounds,
encompassing rather a wide range of U-U distances (seeF ig. I), for which extremely large y-values at
low temperatures have been revealed.
A large variation of interesting behaviour has been noted with these compounds. See the
reviews by Stewart [84Sl] up to 1984, and Trot [87Tl]. The most extensive review has been
recently prepared by Ott and Fisk [8701] as well as Grewe and Steglich [91Gl]. Seea lso Franse and
Gersdorf in Landolt-Bornstein, NS, vol. 111/19fl, pp. 137-193, the part concerning UPt, [91Fl].
The systems UBe,, and UPt,, behaving as strongly temperature-dependent paramagnetic
materials, are puzzling bulk superconductors at temperatures below 1 K. Their superconductivity
arises probably from the pairing of strongly coupled f-electrons. Enormously large effective masses
(the order of magnitude of which is about 100 ... 300 m,) have been observed, hence the name “heavy-
fermion (HF) systems”.
Recent band structure calculations [85Tl, 85Pl], and resonant photoemission (PES) and
bremsstrahlung isochromat (BIS) spectra for UBe,, [84Wl] and UPt, [87Al] have shown the
existence of relatively narrow f-bands pinned at E, (seeF ig. l), the peaks of their DOS’s are at least
one to two orders of magnitude wider (W N 0.1 eV) and of smaller heights than those deduced from
the low-temperature specific heat data. Nevertheless, it is difficult to explain why these materials with
such a high density of states at the Fermi level in some casesf avour the superconducting state. Among
the ternary compounds exhibiting superconducting properties are URu,Si, and the recently dis-
covered UNi,AI, and UPd,Al,, all three compounds belonging to the HF systems.
Finally, four other compounds, NpBe,, (see Fig. 83) UCu, (Fig. 99), U,Zn,, (Fig. 162) and
UCd,, (Fig. 176) should be mentioned for which large y(O)-valuesa nd the simultaneous onset of
magnetic order have been reported. As has been pointed out (see [84Sl]), the y-values determined
from the heat capacity data above the transition point T, are drastically reduced just below this
temperature. A similar behaviour has already been described for NpSn, (Fig. 306), but with relatively
lower values of the corresponding y’s, i.e., yp for T > T,, and y(O)f or T = 0 K. However, the ratio
y(O)/y, is usually between 0.6 and 0.7.
A striking feature of all these HF systems is the strongly temperature-dependent magnetic
susceptibility observed down to the lowest temperatures and following often a Curie-Weiss law, or its
modification, typical of strongly localized systems.
All of these HF systems exhibit an anomalous electrical behaviour (see for example Fig. 19).
Another characteristic feature of the HF systemsi s a large magnetoresistivity. As Fig. 24a illustrates,
for example, this quantity approaches for UBe,, at 1.3 K and in the magnetic field of pLoH= 14T a
value of w 35% of the zero-field value.
In the literature some authors have tried to generate the HF state by forming solid solutions
between, for example, the spin-fluctuator USn, and antiferromagnetically ordered UIn, (Fig. 301~)o r
UPb, (Fig. 318a).
This is possible, due to achieving an appropriate hybridization state between 5f electrons of
uranium and valence electrons of group 3B and 4B metals [85Kl]. At the same time it should be
mentioned that the HF state can be easily destroyed by internal stresseso r impurities (Fig. 18). This
last fact demonstrates that the HF state is of a very delicate nature, existing in subtle equilibrium with
such phenomena like spin or valence fluctuations resulting from a strong interaction of the 5f states
with the band states.
Land&-Bdmstein
New Series IIIj19f2
4 3.4.1 An-main group element: introduction [Ref. p. 7
3.4.1.2 Binary and pseudo-binary compounds
In the past the most extensively studied actinide compounds were those with the AnM,
stoichiometry which cover the region around the Hill-limit (seeF ig. I) and thus can show properties
from nonmagnetic, through spin-fluctuation and itinerant-electron magnetism, to increasingly local-
ized magnetic behaviour.
An archetype of a SF system among the actinide compounds is UAI,, and for this reason this
compound has been thoroughly investigated in view of this effect [77Bl]. All the low-temperature
measurements made on this compound, like magnetic susceptibility at ambient pressure (a T*-
saturation in accordance with Fig. 194)a nd under pressure (fairly large decreasein X-value - Fig. 197),
electrical resistivity (a T*-dependence - Fig. 203), high-field magnetization (suppression of the SF
effect - Fig. 200) heat capacity at zero field (a T* In T/T,, upturn in C/T - Fig. 206) and in high
magnetic fields (only small change - Fig. 207) photoemission (evidence of a fairly narrow 5f band
pinned at E, - Fig. 192) and finally inelastic neutron scattering (only a quasi-elastic peak a few tenth
of an eV wide - Fig. 209) confirm the properties expected from the theory.
Nevertheless, the anomalous temperature characteristics of various properties of UAI, could also
be explained by an one-electron band structure effect without necessity of referring to the SF inter-
actions [SSDl]. A value of the spin-fluctuation temperature T,, = 25 K has been established for UAI,
from various experimental data. At higher temperatures (T > 100 K) the magnetic susceptibility
follows a modified Curie-Weiss law (Fig. 194) and the extracted SF contribution to the electrical
resistivity goes through a broad maximum at w 100 K and then decreasesa s a “dense Kondo” system,
i.e., as In T (seeF ournier and TroC in [85F2]). It is worth noticing that the SF behaviour disappears
rapidly when alloying UAl, with ThAI, (Fig. 213), YAl, (Fig. 218) and GdAl, (Fig. 227), as well as
with PuAI, (Figs. 240 and 242).
A similar, but less deeply investigated behaviour has been found for other phases such as UAI,
(Fig. 248), PuZn, (Fig. 170) and other uranium compounds with Co, Ir, Pt of 1:2 stoichiometry, not
being reviewed here. There are also SF candidates among the AuCu,-type compounds, like UAl, and
USn, (Fig. 296). However, no characteristic TZ In T/T,, upturn in C/T in the low-temperature heat
capacity has been found for the latter compounds (Figs. 294 and 297).
The compounds exhibiting an IEM according to the Stoner-Edwards-Wohlfarth theory (1968) are
characterized by very small values of ps and of the magnetic entropy, Smagtrh e latter usually being
much smaller than R In 2. On the other hand, they often exhibit a rather large value of EDOS at E,,
deduced from y(O),a nd also large values of the differential magnetic susceptibility, xHF,m easured at
high magnetic fields.
The best known examples for such a behaviour among the actinide intermetallics, satisfying fully
or partially the above conditions, are UCu,, U,Zn,, and UCd, 1, and especially NpSn,, all with low
ordering temperatures of 5 a.. 15 K. However, very recently this point of view is changing in the light
of new investigations. For example, the data obtained by 237Np Mijssbauer spectroscopy for NpSn,
under pressures up to ~6.2 GPa [90Kl] have shown a behaviour for this compound typical of
localized 5f electrons.
A very interesting behaviour has been observed for the actinide borides. For example, while pure
UB, (hexagonal AlB,-type) and UB, (tetragonal ThB,-type) are temperature-independent or weakly
temperature-dependent paramagnets, respectively (Fig. 346), NpB, (Fig. 365) as well as the solid
solutions (U,Y)B, (Fig. 354) (U,La)B, and (U,Lu)B, (Fig. 353) in a limited range of composition, are
all itinerant-electron ferromagnets, and NpB, is likely an itinerant antiferromagnet (Fig. 371).
The other AnM, phases with different crystal structures, like UHg, and UGa, (AlB,-type) or
UGe, (ZrSi,-type), etc., show more or less localized f-electron magnetic properties, which can be
normally treated in terms of the crystal-field (CEF) interaction. The latter leads usually to an
extremely large anisotropy in magnetic properties. as is the case for UGe, (Figs. 434-437). On the
other hand, the large cyclotron massesf ound for this compound from the dHvA effect indicate the 5f-
electron are itinerant and strongly correlated with the spin-fluctuation [92Sl].
Landoh-B6mstein
New Series 111’1912
Ref. p. 73 3.4.1 An-main group element: introduction 5
In recent years it has become clear that the 5f electrons may have an itinerant character also in the
compounds in which the An-An distances are fairly far from the Hill limit, as for example in the
AuCu,-type compounds of both kinds of p-bonding, UAl,, USi,, UGe, and those with the 4d-
bonding, URh,, UIr,, etc. All these intermetallics are known to show TIP at low temperatures, with
moderate y-values of 15 ..a 40 mJ mol- ’ K-’ (Fig. 297). The samec oncerns UT, compounds with the
AuBe,-type structure. For details see [90Tl].
As shown either by de Haas-van Alphen (dHvA) and resonant photoemission measurementso r by
band structure calculations, the 5f electron states hybridize considerably with the ligand states p or d
in these two groups of compounds, respectively (seef or referencest he appropriate chapters in [84Fl]
and [85F2]).
Very detailed studies of UGe, single crystals (Figs. 444, 445, 447) have provided an important
insight into the systematics of all these p-d compounds. Unexpectedly, a large charge transfer has been
found, which gives rise to an appreciable ionic bonding in these metallic materials. Furthermore, it
appears that the conduction bands (M 1 eV wide) are formed of U-f and Ge-p hybrides, but rather a
complex valence band is formed of U-d and Ge-p hybridized states. Hence the observed distinct
trend towards more localized orbital behaviour on going from a small-size ligand (Si) to considerably
larger ones (Sn, Pb) is predominantly due to an increasingly successfulc ompetition between the ligand
orbitals themselves (direct contact), thus allowing a large charge transfer. This mechanism, being
compatible with the band calculations, leads to a rather localized ground state for USn, and,
doubtless, for UPb,. For the latter compound an antiferromagnetic order has been reported
(Fig. 286), whereas the SF behaviour of USn, (p cc T2 - Fig. 296, X-levelling off - Fig. 286, and
y(O)= 169 mJmol-l Ke2 - Fig. 297) seems to be most apparent. Indeed, as shown by Lin et al.
[85Ll], USn, is a highly enhanced paramagnetic system which is very close to a magnetic instability.
On alloying with small amounts of UPb,, it exhibits a transition into the antiferromagnetic state
(Fig. 318).
The above idea is even more apparent for the compounds with group 3B elements, namely UAl,,
UGa,, UIn, and UTl,. The latter three compounds are antiferromagnetic at low temperatures
(Fig. 295), with the localization occurring earlier, i.e. for UGa,, due to the atomic radii of the group 3B
ligands being larger than those of the group 4B ligands in the same row of the periodic table. As
Figs. 277-279 illustrate, the antiferromagnetic properties of UGa, are rapidly destroyed by alloying
with UGe,, without forming an intermediate heavy-fermion state. As we have already mentioned
above, such a state is believed to be generated in U(Sn, -XInX)3s olid solutions (Fig. 301).
A rather unusual place among the actinide compounds is occupied by actinide hydrides, reviewed
in subsect.3 .4.3.1.T he foundation of the band structure of these materials has been laid by Switendick
[7OSl, 71S1,76Sl, SOSl], whereas more detailed calculations have been performed by Ward (B-UH,
[79Wl]) and Switendick (a- and P-UH, [82Sl]). From Pa to Am the trihydride AnH, phases are
known, being, however, thermally unstable. As an example Fig. 321 presents a phase diagram of the
U-rich U-H system. Only P-trihydrides of Pa and U have a different crystal structure (cubic B-W) than
the remaining of such hydrides (hexagonal GdH,-type). Furthermore, for Th and Np to Bk, there exist
also dihydrides AnH, +x with an extended range of homogeneity (except for tetragonal ThH,) up to
x z 0.8, crystallizing in the CaF,-type of cubic crystal structure (see,e .g., Ward in [85Fl]).
P-UH,, together with P-UD,, was identified by Trzebiatowski et al. [54Tl] to be the first
magnetically ordered actinide material. As shown in Fig. 322, the B-UH, structure is complex and
occurs with two coexisting sublattices, one with metallic bonding assigned to f-f overlap and the
second having more spread U-U separations. It is surprising that these two positions of uranium
atoms give rise to the samev alue of the net magnetic moment (pu w 1.45 uB)( see[ SSBl] and [91Ll]).
It is interesting to note that no Np-hydrides exhibit a magnetically ordered state and that their
paramagnetic properties can be well understood by considering a CEF effect (Fig. 336). In contrast to
the latter compounds, all the PuH2+, compositions show ferromagnetic transitions [SSWl], the
Land&Biirnstein
New Series III/1912
6 3.4.1 An-main group element: introduction [Ref. p. 7
temperatures of which increase with increasing x (Fig. 338). However, there is a disagreement for the
composition near PuH,: Aldred et al. [79Al] claimed this compound to be antiferromagnetically
ordered (Fig. 337).T he magnetic properties of the heavier actinide hydrides have not been recognized
so far.
In the past much attention has been paid to the actinide carbides becauseo f their significance in
nuclear technology. Some detailed knowledge about the physical properties of actinide carbides,
together with borides and silicides has been summarized in a chapter by P.E. Potter in the textbook
“The Chemistry of the Actinides” edited by J.C. Bailar et al., Pergamon Press in 1975 [75Pl]. In
general, they appear as mono-, sesqui- and dicarbides, often with some range of homogeneity. The
latter compositions, only occurring for Th, Pa and U, have usually more than one crystal form.
The electronic structures of Th-, Pa-, U- and Np-monocarbides based on the quasi-self-consistent
relativistic energy band calculation have been reported by Mallet [82Ml]. The major observation
was a rapid change in character of the bonds at the Fermi energy from d to f at PaC, and the
increasing trend in localization of the 5f electrons across the series, but with still important 5f
participation in the bonding.
Their magnetic properties vary from typical Pauli paramagnetism (ThC, ThC,, UC and UC,) as
illustrated in Figs. 376 and 381, to those showing magnetic order at low temperatures, e.g.,i n the cases
of NpC and PuC. Moreover, the former exhibits a transition from a ferromagnetic to an antiferromag-
netic state (Fig. 394). Most controversial is U,C,, for which the anomaly occurring in the magnetic
susceptibility at 54 K (Fig. 388) has not been confirmed by specific heat (Fig. 401) and neutron
diffraction measurements [66Dl].
3.4.1.3 Arrangement of tables and figures
Section 3.4 contains the magnetic and related properties of the binary (or pseudobinary)
compounds of actinides with the elements of main groups of the periodic table. However, also
included are those physical properties which are necessary for the understanding of the magnetic
behaviour of the compounds listed.
In the present compilation the numerical data, selected from current literature, are presented in
the form of tables and figures. The order of presentation is as follows: the data are arranged according
to the position of the nonactinide element in the periodic table, first the binary compounds with
nontransition metals (subsect. 3.4.2) and then with the nonmetallic partners (subsect. 3.4.3). The
materials are collected according to stoichiometry with increasing content of the nonactinide
component and finally according to increasing atomic number of a given actinide element. For
example, we present the thorium, uranium, neptunium, plutonium etc., dialuminides and then
trialuminides of the same elements. The pseudobinary systems are located immediately after the
binary compounds in which the actinide or nonactinide component was substituted by the other
element.
The information compiled in the tables (or surveys) and figures may be subdivided into three
distinct groups:
(a) Structural and electronic properties:
lattice parameters, their temperature and pressure dependences,
crystal structure types, sometimesa lso atomic positions, and finally electronic structural data, like
band structure, Fermi surface, photoemission spectra etc.
LandokB6mstein
New Scrin III;1912
6 3.4.1 An-main group element: introduction [Ref. p. 7
temperatures of which increase with increasing x (Fig. 338). However, there is a disagreement for the
composition near PuH,: Aldred et al. [79Al] claimed this compound to be antiferromagnetically
ordered (Fig. 337).T he magnetic properties of the heavier actinide hydrides have not been recognized
so far.
In the past much attention has been paid to the actinide carbides becauseo f their significance in
nuclear technology. Some detailed knowledge about the physical properties of actinide carbides,
together with borides and silicides has been summarized in a chapter by P.E. Potter in the textbook
“The Chemistry of the Actinides” edited by J.C. Bailar et al., Pergamon Press in 1975 [75Pl]. In
general, they appear as mono-, sesqui- and dicarbides, often with some range of homogeneity. The
latter compositions, only occurring for Th, Pa and U, have usually more than one crystal form.
The electronic structures of Th-, Pa-, U- and Np-monocarbides based on the quasi-self-consistent
relativistic energy band calculation have been reported by Mallet [82Ml]. The major observation
was a rapid change in character of the bonds at the Fermi energy from d to f at PaC, and the
increasing trend in localization of the 5f electrons across the series, but with still important 5f
participation in the bonding.
Their magnetic properties vary from typical Pauli paramagnetism (ThC, ThC,, UC and UC,) as
illustrated in Figs. 376 and 381, to those showing magnetic order at low temperatures, e.g.,i n the cases
of NpC and PuC. Moreover, the former exhibits a transition from a ferromagnetic to an antiferromag-
netic state (Fig. 394). Most controversial is U,C,, for which the anomaly occurring in the magnetic
susceptibility at 54 K (Fig. 388) has not been confirmed by specific heat (Fig. 401) and neutron
diffraction measurements [66Dl].
3.4.1.3 Arrangement of tables and figures
Section 3.4 contains the magnetic and related properties of the binary (or pseudobinary)
compounds of actinides with the elements of main groups of the periodic table. However, also
included are those physical properties which are necessary for the understanding of the magnetic
behaviour of the compounds listed.
In the present compilation the numerical data, selected from current literature, are presented in
the form of tables and figures. The order of presentation is as follows: the data are arranged according
to the position of the nonactinide element in the periodic table, first the binary compounds with
nontransition metals (subsect. 3.4.2) and then with the nonmetallic partners (subsect. 3.4.3). The
materials are collected according to stoichiometry with increasing content of the nonactinide
component and finally according to increasing atomic number of a given actinide element. For
example, we present the thorium, uranium, neptunium, plutonium etc., dialuminides and then
trialuminides of the same elements. The pseudobinary systems are located immediately after the
binary compounds in which the actinide or nonactinide component was substituted by the other
element.
The information compiled in the tables (or surveys) and figures may be subdivided into three
distinct groups:
(a) Structural and electronic properties:
lattice parameters, their temperature and pressure dependences,
crystal structure types, sometimesa lso atomic positions, and finally electronic structural data, like
band structure, Fermi surface, photoemission spectra etc.
LandokB6mstein
New Scrin III;1912
Referencesf or 3.4.1 7
(b) Magnetic properties:
type of magnetism,
magnetic structure, if known,
paramagnetic Curie temperature 0, temperature of magnetic transition or of anomaly of
unknown origin,
ordered (pAn) saturation (p,), and effective (p,,,) magnetic moments,
temperature-independent (x0), or extrapolated-to-O-K (x(0)) magnetic susceptibilities.
(c) Other properties:
electrical resistivity p at room temperature (RT),
superconducting transition temperature T,, and other transport properties such as:
magnetoresistivity,
Seebecka nd Hall coefficients,
thermodynamic properties, including the temperature of the ,&type anomaly, coefficient of
electronic specific heat y(O),D ebye temperature On, as well as
NMR and Miissbauer effect data, if available.
Particularly broad spacei s devoted to the so-called heavy-fermion systemsw hich now are part of
a novel, most quickly developing, branch of solid-state physics. For this reason this subject is far from
being complete and very soon, after closing this chapter, may turn out to be out-of-date.
References for 3.4.1
54Tl Trzebiatowski, W., Sliwa, A., Stalinski, B.: Roczniki Chem. 28 (1954) 12.
66Dl De Novion, C.H., Krebs, J.P., Meriel, P.: C. R. Acad. Sci. (Paris) 263 (1966) 457.
7OSl Switendick, A.C.: J. Less-Common Met. 8 (1970) 1463.
71Sl Switendick, A.C.: Int. J. Quant. Chem. 5 (1971) 459.
74Fl Freeman, A.J., Darby, J.B. (eds.), in: The Actinides: Electronic Structure and Related
Properties, New York: Academic Press 1974, ~01s.I and II.
75Pl Potter, P.E., in: The Chemistry of the Actinides, Bailar, J.C. et al. (eds.), Pergamon Press
1975, p. 357.
76Sl Switendick, A.C.: J. Less-Common Met. 49 (1976) 283.
77Bl Brodsky, M.B., Trainor, R.J.: Physica B 91 (1977) 271.
79Al Aldred, A.T., Cinader, G., Lam, D.J., Weber, L.W.: Phys. Rev. B 19 (1979) 300.
79Wl Ward, J.W., Cox, L.E., Smith, J.L., Stewart, G.R., Wood, J.H.: J. Phys. (Paris) Colloq. 40
(1979) c4-15.
8OSl Switendick, A.C.: J. Less-Common Met. 74 (1980) 199.
82Ml Mallet, C.P: J. Phys. C 15 (1982) 6361.
82Sl Switendick, A.C.: J. Less-Common Met. 88 (1982) 257.
83El Erdiis, P., Robinson, J.M., The Physics of Actinide Compounds, New York: Plenum Press
1983.
84Fl Freeman, A.J., Lander, G.H (eds.), in: Handbook on the Physics and Chemistry of the
Actinides, Amsterdam: North Holland, 1984, vol. I.
84Sl Stewart, G.R.: Rev. Mod. Phys. 56 (1984) 755.
84Wl Wuilloud, W., Baer, Y., Ott, H.R., Fisk, Z., Smith, J.L.: Phys. Rev. B 29 (1984) 5228.
85Al Allen, J.W., Oh, S.J., Cox, L.E., Ellis, W.P., Wire, M.S., Fisk. Z., Smith, J.L., Pate, B.B.,
Lindau, I., Arko, A.J.: Phys. Rev. Lett. 54 (1985) 2635.
85Bl Bartscher, W., Boeuf, A., Caciuffo, R., Fournier, J.M., Kuhs, W.F., Rebizant, J., Rustichelli,
F.: Solid State Commun. 53 (1985) 423.
85Dl De Groot, R.A., Koelling, D.D., Weger, M.: Phys. Rev. B 32 (1985) 2659.
85Fl Freeman, A.J., Keller, C. (eds.), in: Handbook on the Physics and Chemistry of the
Actinides, Amsterdam: North Holland, 1985, vol. III.
Landolt-BBmstein
New Series IW19f2
Referencesf or 3.4.1 7
(b) Magnetic properties:
type of magnetism,
magnetic structure, if known,
paramagnetic Curie temperature 0, temperature of magnetic transition or of anomaly of
unknown origin,
ordered (pAn) saturation (p,), and effective (p,,,) magnetic moments,
temperature-independent (x0), or extrapolated-to-O-K (x(0)) magnetic susceptibilities.
(c) Other properties:
electrical resistivity p at room temperature (RT),
superconducting transition temperature T,, and other transport properties such as:
magnetoresistivity,
Seebecka nd Hall coefficients,
thermodynamic properties, including the temperature of the ,&type anomaly, coefficient of
electronic specific heat y(O),D ebye temperature On, as well as
NMR and Miissbauer effect data, if available.
Particularly broad spacei s devoted to the so-called heavy-fermion systemsw hich now are part of
a novel, most quickly developing, branch of solid-state physics. For this reason this subject is far from
being complete and very soon, after closing this chapter, may turn out to be out-of-date.
References for 3.4.1
54Tl Trzebiatowski, W., Sliwa, A., Stalinski, B.: Roczniki Chem. 28 (1954) 12.
66Dl De Novion, C.H., Krebs, J.P., Meriel, P.: C. R. Acad. Sci. (Paris) 263 (1966) 457.
7OSl Switendick, A.C.: J. Less-Common Met. 8 (1970) 1463.
71Sl Switendick, A.C.: Int. J. Quant. Chem. 5 (1971) 459.
74Fl Freeman, A.J., Darby, J.B. (eds.), in: The Actinides: Electronic Structure and Related
Properties, New York: Academic Press 1974, ~01s.I and II.
75Pl Potter, P.E., in: The Chemistry of the Actinides, Bailar, J.C. et al. (eds.), Pergamon Press
1975, p. 357.
76Sl Switendick, A.C.: J. Less-Common Met. 49 (1976) 283.
77Bl Brodsky, M.B., Trainor, R.J.: Physica B 91 (1977) 271.
79Al Aldred, A.T., Cinader, G., Lam, D.J., Weber, L.W.: Phys. Rev. B 19 (1979) 300.
79Wl Ward, J.W., Cox, L.E., Smith, J.L., Stewart, G.R., Wood, J.H.: J. Phys. (Paris) Colloq. 40
(1979) c4-15.
8OSl Switendick, A.C.: J. Less-Common Met. 74 (1980) 199.
82Ml Mallet, C.P: J. Phys. C 15 (1982) 6361.
82Sl Switendick, A.C.: J. Less-Common Met. 88 (1982) 257.
83El Erdiis, P., Robinson, J.M., The Physics of Actinide Compounds, New York: Plenum Press
1983.
84Fl Freeman, A.J., Lander, G.H (eds.), in: Handbook on the Physics and Chemistry of the
Actinides, Amsterdam: North Holland, 1984, vol. I.
84Sl Stewart, G.R.: Rev. Mod. Phys. 56 (1984) 755.
84Wl Wuilloud, W., Baer, Y., Ott, H.R., Fisk, Z., Smith, J.L.: Phys. Rev. B 29 (1984) 5228.
85Al Allen, J.W., Oh, S.J., Cox, L.E., Ellis, W.P., Wire, M.S., Fisk. Z., Smith, J.L., Pate, B.B.,
Lindau, I., Arko, A.J.: Phys. Rev. Lett. 54 (1985) 2635.
85Bl Bartscher, W., Boeuf, A., Caciuffo, R., Fournier, J.M., Kuhs, W.F., Rebizant, J., Rustichelli,
F.: Solid State Commun. 53 (1985) 423.
85Dl De Groot, R.A., Koelling, D.D., Weger, M.: Phys. Rev. B 32 (1985) 2659.
85Fl Freeman, A.J., Keller, C. (eds.), in: Handbook on the Physics and Chemistry of the
Actinides, Amsterdam: North Holland, 1985, vol. III.
Landolt-BBmstein
New Series IW19f2
8 Referencesf or 3.4.1
85F2 Freeman, A.J., Lander, G.H. (eds.), in: Handbook on the Physics and Chemistry of the
Actinides, Amsterdam: North Holland, 1985, vol. II.
85Kl Koelling, D.D., Dunlap, B.D., Crabtree, G.W.: Phys. Rev. B 31 (1985) 4966.
85Ll Lin, C.L., Zhou, L.W., Crow, J.E., Guertin, R.P.: J. Appl. Phys. 57 (1985) 3146.
85Pl Pickett, W.E., Krakauer, H., Wang, C.S.: Physica B 135 (1985) 31.
85Tl Takegahara, K., Harima, H., Kasuya, T.: J. Magn. Magn. Mater. 47-48 (1985) 263.
85Wl Willis, J.O., Ward, J.W., Smith, J.L., Kosiewicz, S.T., Haschke, J.M., Hodges, A.E.: Physica
B 130 (1985) 527.
87Al Allen, J.W., Kang, J.S., Lassailly, Y., Maple, M.B., Torikachvili, M.S., Ellis, W., Pate, B.,
Lindau, I.: Solid State Commun. 61 (1987) 183.
8701 Ott, H.R., Fisk, Z., in: Handbook on the Physics and Chemistry of the Actinides, Freeman,
A.J., Lander, G.H. (eds.), Amsterdam: North Holland, 1987, vol. 5, p. 85.
87Tl Trot, R.: Acta Magnetica IV (1987) 67.
88Sl Sechovsky, V., Havela, L., in: Ferromagnetic Materials, Wohlfarth, E.P., Buschow, K.H.J.
(eds.), Amsterdam: Elsevier Science Publ. BV 1988, vol. 4., p. 309.
90K 1 Kalvius, G.M., Zwirner, S., Potzel, U., Moser, J., Potzel, W., Litterst, F.J., Gal, J., Fredo, S.,
Yaar, I., Spirlet, J.C.: Phys. Rev. Lett. 65 (1990) 2290.
90Tl Trot, R., Tran, V.H., Zolnierek, Z.: J. Magn. Magn. Mater. 90-91 (1990) 405.
91Fl Franse, J.J.M., Gersdorf, R., in: Landolt-Bernstein, New Series,M adelung, 0. (ed.), Berlin:
Springer 1991, vol. 111/19fl, p. 137.
91Gl Grewe, N., Steglich, F., in: Handbook on the Physics and Chemistry of Rare Earths,
Gschneidner, K.A. Jr., Eyring, L. (eds.), Amsterdam: Elsevier Science Publ. BV 1991,
vol. 14, p. 343.
91Ll Lawson, A.C., Goldstone, J.A., Huber, J.G., Giorgi, A.L., Conant, J.W., Severing, A., Cort,
B., Robinson, R.A.: J. Appl. Phys. 69 (1991) 5112.
92Sl Satoh, K., Yun, S.W., Ukon, I., Umehara, I., &uki, Y., Aoki, H., Uji, S., Shimizu, T.,
Sakamoto, I., Hunt, M., Meeson, P., Probst, P.A., Springford, M.: J. Magn. Magn. Mater.
104-107 (1992) 39.
Land&Eimslcin
New Series 111/1912