SPRINGER BRIEFS IN APPLIED SCIENCES AND TECHNOLOGY THERMAL ENGINEERING AND APPLIED SCIENCE Jihong Al-Ghalith Traian Dumitrică Nano-scale Heat Transfer in Nanostructures Toward Understanding and Engineering Thermal Transport 123 SpringerBriefs in Applied Sciences and Technology Thermal Engineering and Applied Science Serieseditors Janusz Kacprzyk, Polish Academy of Sciences, Systems Research Institute, Warsaw,Poland FrancisA.Kulacki,UniversityofMinnesota,Minneapolis,MN,USA SpringerBriefs present concise summaries of cutting-edge research and practical applications across a wide spectrum of fields. Featuring compact volumes of 50 to 125pages,theseriescoversarangeofcontentfromprofessionaltoacademic. 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Moreinformationaboutthisseriesathttp://www.springernature.com/series/8884 (cid:1) ă Jihong Al-Ghalith Traian Dumitric Nano-scale Heat Transfer in Nanostructures Toward Understanding and Engineering Thermal Transport JihongAl-Ghalith TraianDumitrică DepartmentofCivil,Environmental DepartmentofMechanicalEngineering andGeo-Engineering UniversityofMinnesota UniversityofMinnesota Minneapolis,MN,USA Minneapolis,MN,USA ISSN2191-530X ISSN2191-5318 (electronic) SpringerBriefsinAppliedSciencesandTechnology ISSN2193-2530 ISSN2193-2549 (electronic) ThermalEngineeringandAppliedScience ISBN978-3-319-73881-9 ISBN978-3-319-73882-6 (eBook) https://doi.org/10.1007/978-3-319-73882-6 LibraryofCongressControlNumber:2018932554 ©TheAuthor(s)2018 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartofthe materialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation, broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology nowknownorhereafterdeveloped. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant protectivelawsandregulationsandthereforefreeforgeneraluse. The publisher, the authors and the editors are safe to assume that the advice and information in this bookarebelievedtobetrueandaccurateatthedateofpublication.Neitherthepublishernortheauthorsor theeditorsgiveawarranty,expressorimplied,withrespecttothematerialcontainedhereinorforany errorsoromissionsthatmayhavebeenmade.Thepublisherremainsneutralwithregardtojurisdictional claimsinpublishedmapsandinstitutionalaffiliations. Printedonacid-freepaper ThisSpringerimprintispublishedbySpringerNature TheregisteredcompanyisSpringerInternationalPublishingAG Theregisteredcompanyaddressis:Gewerbestrasse11,6330Cham,Switzerland Preface Heat transfer is vital throughout research and industry. Substantial endeavors have beeninvestedintothisfieldofstudy.Withthedevelopmentoftechnologyinsmall- scale manufacturing and applications, heat transfer in nanomaterials has attracted greatinterestduetoitsimportantapplicationsinmodernindustry,suchaselectronic devices,sensors,switches,aswellascoatingengineering.Thisbookfocusesonheat transfer in nanostructures and amorphous materials, in which the arrangement of atoms is crucial for the effectiveness of heat transport. Defects and mechanical deformations in a material which cause displacement or reconfiguration of atoms relativetothatmaterial’s“normal”or“pristine”conditioncandramaticallyinfluence its heat transport efficiency. Since the 1950s, there has been little progress in understanding the defects-thermal transport property relationship. Using novel numericaltechniquesandlarge-scalecomputationsperformedonmodernsupercom- puters,severalstudiesofheattransportinnanomaterialscontainingvariousdefects and mechanical deformations have been conducted. From the properties of atomic vibrationsinsimulations,theeffects thesedeformationshaveonheattransportcan bededuced. Threestudiesindifferentnanomaterialsarepresentedinthisbook.Thestudyof heattransportinscrew-dislocatednanowireswithlowthermalconductivitiesintheir bulkformrepresentstheknowledgebaseneededforengineeringthermaltransportin advancedthermoelectricandelectronicmaterials.Thisresearchalsosuggestsanew potentialroutetolowerthermalconductivity,whichcouldpromotethermoelectric- ity. The study of high-temperature coating composite materials helps with the understandingoftheroleplayedbycompositionandthestructuralcharacterization, whichisdifficulttobeapproachedbyexperiments.Themethodappliedinstudying the composition-structure-property relationship of amorphous silicon-boron-nitride networkscouldalsobeusedintheinvestigationofvariousothersimilarcomposite materials. Such studies can further provide guidance in designing ultrahigh- temperature ceramics, including space shuttle thermal protection system materials andhigh-temperature-resistancecoating.Theunderstandingoftheimpactofbend- ing and collapsing on thermal transport along carbon nanotubes is important as v vi Preface carbon nanotubes are excellent material candidates in a variety of applications, including thermal interface materials, thermal switches, and composite materials. Theatomisticstudyofcarbonnanotubescanalsoprovidecrucialguidanceinmulti- scale study ofthematerials toenable large-scalethermalbehaviorprediction. T.D. would like to thank the Hanse Wissenschaftskolleg Delmenhorst, Germany for hospitality during the preparation of this manuscript. J.A. would like to thank GabrielAl-Ghalithforthehelpineditingthebook. Minneapolis,MN,USA JihongAl-Ghalith TraianDumitrică Contents 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 HeatTransfer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 MaterialsofInterest. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2.1 Screw-DislocatedThermoelectricNanowires. . . . . . . . . . . . 2 1.2.2 AmorphousSilicon-Boron-NitrideNetwork. . . . . . . . . . . . . 3 1.2.3 CarbonNanotubes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 TheoreticalBackground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.3.1 DislocationTheory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.3.2 TheClassicalTheoryofHeatTransfer. . . . . . . . . . . . . . . . 7 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2 Methodology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2.1 MolecularDynamicsandBoundaryConditions. . . . . . . . . . . . . . . 17 2.2 ThermodynamicEnsembles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.1 MicrocanonicalEnsemble. . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.2 CanonicalEnsembleandIsothermal-IsobaricEnsemble. . . . 20 2.3 PhononStudyMethods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.3.1 TheGreen-KuboMethod. . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.3.2 TheDirectMethod. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.3.3 PhononDispersionRelation. . . . . . . . . . . . . . . . . . . . . . . . 23 2.3.4 PhononRelaxationTime. . . . . . . . . . . . . . . . . . . . . . . . . . 24 2.3.5 PhononDensityofStates. . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.4 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3 Screw-DislocatedNanostructures. . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.1 Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.2 SiliconNanowiresandNanotubes. . . . . . . . . . . . . . . . . . . . . . . . . 28 3.2.1 StructurePreparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.2.2 ThermalPropertiesCalculation. . . . . . . . . . . . . . . . . . . . . . 30 3.2.3 ResultsandDiscussion. . . . . . . . . .. . . . . . . . . . . .. . . . . . 31 vii viii Contents 3.3 LeadSelenideandSiliconGermaniumNanowires. . . . . . . . . . . . . 32 3.3.1 StructurePreparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 3.3.2 ThermalPropertiesCalculation. . . . . . . . . . . . . . . . . . . . . . 34 3.3.3 ResultsandDiscussion. . . . . . . . . .. . . . . . . . . . . .. . . . . . 35 3.4 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 4 AmorphousSilicon-Boron-NitrideNetworks. . . . . . . . . . . . . . . . . . . . 41 4.1 StructurePreparation.. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . 41 4.2 ThermalPropertiesCalculation. . . . . . . . . . . . . . . . . . . . . . . . . . . 48 4.3 ResultsandDiscussions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 4.4 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 5 DeformedCarbonNanotubes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5.1 Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5.2 PurelyBentCarbonNanotubes. . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5.2.1 StructurePreparations. . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5.2.2 ThermalPropertiesCalculation. . . . . . . . . . . . . . . . . . . . . . 59 5.2.3 ResultsandDiscussion. . . . . . . . . .. . . . . . . . . . . .. . . . . . 61 5.3 CollapsedCarbonNanotubes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 5.3.1 StructurePreparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 5.3.2 ThermalPropertiesCalculation. . . . . . . . . . . . . . . . . . . . . . 65 5.3.3 ResultsandDiscussion. . . . . . . . . .. . . . . . . . . . . .. . . . . . 67 5.4 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 6 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Symbols ZT Figureofmerit κ Thermalconductivity,W/mK S Seebeckcoefficient,V/K σ Electricalconductivity,S/m C Heatcapacity,J/kgK v v Velocity,m/s τ Phononlifetime,s ω Frequency,s-1 m Mass,kg x,y,z Positions/directionsinCartesiancoordinates,m t Time,s φ Potentialenergy,J j Heatflux,W/m2 k Boltzmannconstant,1.38064852(cid:3)10-23J/K B T Temperature,K u Displacementvector,m D Dynamicalmatrix ΔH Enthalpyofformation,J f Y Young’smodulus,N/m2 ix