Neutron scattering study on R_1tn2PdSi_1tn3 (R=Ho, Er, Tm) compounds [Elektronische Ressource] / vorgelegt von Fei Tang

Technische Universit¨at DresdenFakult¨at Mathematik und NaturwissenschaftenFachrichtung PhysikInstitut fu¨r Festk¨orperphysikNeutron scattering study onR PdSi2 3(R = Ho, Er, Tm) compoundsDissertationzur Erlangung des akademischen GradesDoctor rerum naturaliumvorgelegt vonFei Tanggeboren am 06.06.1981 in Sichuan, ChinaOktober, 20101. Gutachter: Professor Dr. Michael Loewenhaupt2. Gutachter: Professor Dr. Frank SteglichEingereicht am: 04.10.2010Verteidigt am: 14.12.2010iiAbstractPrevious studies on the family of inter-metallic rare-earth compounds R PdSi re-2 3vealed multifaceted magnetic properties, for instance, spin-glass like behavior. Exper-imental observations include: Signs of a crystallographic superstructure, complicatedmagneticstructuresbothinzerofieldandinappliedmagneticfieldsaswellasagenericphase in applied fields for compounds in the series with the heavy rare-earthsR = Gd,Tb, Dy, Ho, Er and Tm.This thesis expands the studies on the magnetic properties of R PdSi employing2 3mainlyneutronscatteringonsinglecrystalswiththefocusonthecompoundswithR=Ho,ErandTm. Adetailedanalysisofthecrystallographicsuperstructureusingmodu-lationwaveapproachandgrouptheoryispresented. Theresultingstructureimpliestheexistence of two different rare-earth sites with reduced symmetry and an arrangementofthedifferentsitesaccordingtosequencesasdeterminedbythesuperstructure.