Properties of Ni-Mn Based Heusler alloys with martensitic transition

182 Pages·2014·10.99 MB·English

PROPERTIES OF Ni-Mn BASED HEUSLER ALLOYS
WITH MARTENSITIC TRANSITION
Thesis submitted for the degree of
Doctor of Philosophy (Science)
in
Physics (Experimental)
by
Sandeep Singh
Department of Physics
University of Calcutta
July 2014

To my parents

v
Acknowledgements
It is my great pleasure to express my gratitude to all the persons for their help and encour-
agement. First I would like to express my special appreciation and thanks to my supervisor Dr.
Chhayabrita Biswas, who has supported me throughout my thesis with her patience and knowl-
edge. In particular, I am very grateful for her continuous assistance, guidance and friendly atti-
tude. Shealwaysencouragedmetogettothebottomofeveryproblemandhelpedtounderstandit
fully. Also,IamverygratefultoherforthefreedomIwasgivenduringmyPhD.
I am grateful to Prof. Kalobaran Maiti and his research group of Tata Institute of Fundamen-
tal Research, for providing XPS and UPS facilities and help with the data acquisition. In his lab
I also learned the techniques of XPS and UPS. Specially, I would like to thank Ganeshda, Deep,
Nishina and Bindudi. Without their help I would not have been able to complete photoemission
experiments.
The large part of the experimental work presented in this thesis were performed at the UGC-
DAE-CSR,Indore. IwouldespeciallyliketoexpressmyappreciationforDr. RajeevRawat,Dr. A.
M.AwasthiandDr. S.R.Barmanforallowingmetousethefacilitiesoftheirlaboratory. Ishould
also take this occasion to thank Prof. I. Das of SINP, Kolkata for initial support by providing the
chemicalsandotherfacilitiesforsamplepreparation. IamgratefultoProf. D.DasofUGC-DAE-
CSR, Kolkata, who provided the SQUID for magnetic measurements. I would also like to thank
Mr. P.V.RajeshforperformingSQUIDmeasurementsforme.
I would like to thank my head of department Prof. P. K. Mukhopadhyay for providing the arc
furnaceforsamplepresentation. IalsoexpressmythankstoDr. B.RajiniKanth,whofirstshowed
me the operation of arc furnace. I must also acknowledge the help of many technical staffs in
variouslabsofSNBoseCentreandothercentres.
I am thankful to my seniors Abhinav Kumar, Prashant Singh, A P Jena, Debraj Ray, Soumyajit
Sarkar, Hirak Kr. Chandra and Kapil Gupta. They always helped and supported me. Abhinav
bhaiya and Prashantji are like elder brothers to me. Whenever I have problems related to com-
puteroranysoftwareitwasalwaysJenajiwhohadtherightanswersforme. InSNBosecampusI
enjoyedthecompanygreatfriends. IamgladtohavefriendslikeRajeevChauhan,SandeepAgar-
wal, Rajib Nath, Abhijit Chakraborty, Tanumay Pramanik, Manotosh Chakraborty, Shahnewaz
Mondal and Sudip Garain who shared their precious time with me and provided cheerful envi-
ronment. I appreciate my juniors Saikat Debnath, Shishir Pandey, Basudeb Mandal, Ruma Das,
Ruma Mandal, Wasim Iqbal, Rajshree Das, Tukun, Tanmoy Ghosh, Dilip Sao for spending joyous
time with me. I am indebted to all of them for providing a stimulating and fun filled environment.
Evening outing with Saikat, Shishir and Basudeb was always refreshing and relaxing. The polit-
ical discussion between Shishir and others (including me) at lunch and dinner table was always
entertaining. IwouldliketothankmylabmateSoumyadiptaPalforhishelpwiththesiscorrections
vi
andusefulscientificdiscussions.
Finally, I would never have been able to complete my thesis without the continued support from
my family. I am grateful to my mother and father for their love and confidence in me. It inspired
meandconstantlydrovemeforward. AlthoughtheyknewverylittleofwhatIwasdoinginmylab,
they always supported and encouraged me, especially when things were not going well. I wish to
thank my elder brothers Shiv Nandan, Shashank and sister in law Alka for continuous motivation,
support and advice. The constant love and support of my younger brothers Kuldeep and Anudeep
issincerelyappreciated.
SandeepSingh
Kolkata,July,2014
vii
List of Publications
Thesis work:
1. SandeepSinghandC.Biswas,“Magnetoresistanceorigininmartensiticandausteniticphases
ofNi2Mn1+xSn1−x",Appl. Phys. Lett. 98,212101(2011).
2. SandeepSingh, Illya Glavatskyy, and C. Biswas,“The influence of quench atomic disorder
on the magnetocaloric properties of Ni-Co-Mn-In alloys", J. Alloys Compd. 601, 108-111
(2014).
3. SandeepSingh,IllyaGlavatskyy,andC.Biswas,“Field-cooledandzero-fieldcooledmagne-
toresistancebehaviorofNi2Mn1+xIn1−x alloys",J.AlloysCompd. (2014).
DOI:http://dx.doi.org/10.1016/j.jallcom.2014.07.012.
4. SandeepSingh, Soumyadipta Pal, and C. Biswas,“Disorder induced resistivity anomaly in
Ni2Mn1+xSn1−x",J.AlloysCompd. (2014).
DOI:http://dx.doi.org/10.1016/j.jallcom.2014.07.072.
5. SandeepSingh, Ganesh Adhikary, D. Biswas, Kalobaran Maiti, and C. Biswas, “Electronic
structuremodificationofNi Mn Sn uponmartensiticphasetransition",AIPConf. Proc.
2 1:4 0:6
1349,849-850(2011).
6. SandeepSingh and C. Biswas, “Disorder induced resistivity changes in Ni2Mn1+xSn1−x",
AIPConf. Proc. 1349,1005-1006(2011).
7. M. Maniraj, S. W. D’ Souza, SandeepSingh, C. Biswas, S. Majumdar, and S. R. Bar-
man,“Electronic structure of nearly stoichiometric Ni-Mn-Sn and Ni-Mn-In", (J. Electron
Spectrosc. Relat. Phenom.) Submitted.
8. Soumyadipta Pal, SandeepSingh, P. Mahadevan, K. Maiti, and C. Maji,“Role of coulomb
correlationintheelectronicstructureofNi-Mn-Sn"Underpreparation.
9. Soumyadipta Pal, SandeepSingh, P. Mahadevan, and C. Maji,“Spin-lattice coupling driven
magneticfieldinducedreversephasetransitioninNi2Mn1+xSn1−x"Underpreparation.
10. C.Maji,SandeepSingh,SoumyadiptaPal,GaneshAdhikary,P.Mahadevan,andKalobaran
Maiti,“Electronic structure influence on instability of martensitic phase of Ni2Mn1+xSn1−x"
Underpreparation.
viii
Contributory work:
1. SandeepSingh , Anchal Dwivedi, R. Dabrowski, and R. Dhar, “Electro-optical features of
anti ferro electric liquid crystal material (S)-(+)-4-(1-methylheptyloxycarbonyl) phenyl 4’-
(6-octanoyloxyhex-1-oxy)biphenyl-4-carboxylateinitsferroandantiferroelectricphases",
PhysicaB406,40-44(2011).
2. R. Dhar, SandeepSingh, I. M. L. Das and R. Dabrowski, “Thermodynamic and dielectric
studies of liquid crystalline compound (S)-(+)-4-(1-methylheptyloxycarbonyl) phenyl 4’-(6-
octanoyloxyhex-1-oxy)biphenyl-4-carboxylate",PhaseTransitions82,251-265(2009).
Contents
TableofContents ix
1 Introduction 1
1.1 Heusleralloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 MartensitictransitioninHeusleralloys . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Advancedfunctionalproperties . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.3.1 Magneticshapememoryeffect . . . . . . . . . . . . . . . . . . . . . . . . 10
1.3.2 Magnetoresistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.3.3 Magnetocaloriceffect . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.4 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.5 Outlineofthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2 Experimentalmethods 23
2.1 Arcmeltingprocess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.2 Scanningelectronmicroscope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.3 EnergydispersiveX-rayanalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.4 Differentialscanningcalorimetry . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.5 X-raydiffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.6 Fourprobemethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2.7 Vibratingsamplemagnetometer . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.8 Superconductingquantuminterferencedevice(SQUID) . . . . . . . . . . . . . . . 31
2.9 Photoelectronspectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.9.1 Theoryofphotoemission . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.9.2 Experimentalsetup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3 Heusleralloypreparationandcharacterization 45
3.1 Samplepreparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.2 Chemicalcomposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.3 Determinationoftransitiontemperatures . . . . . . . . . . . . . . . . . . . . . . . 47
3.4 Surfacemicro-structureatroomtemperature . . . . . . . . . . . . . . . . . . . . . 51
3.5 Crystalstructureatroomtemperature . . . . . . . . . . . . . . . . . . . . . . . . 54
3.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
ix
x CONTENTS
4 Magneticproperty 61
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.2 ResultandDiscussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
4.2.1 Ni2Mn1+xSn1−x alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
4.2.2 Ni2Mn1+xIn1−x alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
4.2.3 CodopedNi-Mn-Inalloys . . . . . . . . . . . . . . . . . . . . . . . . . . 76
4.2.4 Inversemagnetocaloriceffect . . . . . . . . . . . . . . . . . . . . . . . . 79
4.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
5 Electrical-transportproperty 89
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
5.2 ResultandDiscussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
5.2.1 Ni2Mn1+xSn1−x alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
5.2.2 Ni2Mn1+xIn1−x alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
5.2.3 CodopedNi-Mn-Inalloys . . . . . . . . . . . . . . . . . . . . . . . . . . 109
5.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
6 Magneto-transportproperty 119
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
6.2 ResultandDiscussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
6.2.1 Ni2Mn1+xSn1−x alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
6.2.2 Ni2Mn1+xIn1−x alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
6.2.3 CodopedNi-Mn-Inalloys . . . . . . . . . . . . . . . . . . . . . . . . . . 135
6.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
7 Electronicstructure 143
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
7.2 CleansurfacepreparationunderUHV . . . . . . . . . . . . . . . . . . . . . . . . 145
7.3 Dataanalysisprocedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
7.4 ResultandDiscussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
7.4.1 Surfacecharacterization . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
7.4.2 Corelevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
7.4.3 Valenceband . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
7.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167