Non-Kramers doublet ground state in a quaternary cubic compound PrRu_(2)In_(2)Zn_(18) investigated by ultrasonic measurements  

作　　者：张化远 Kazuhei Wakiya Mitsuteru Nakamura Masahito Yoshizawa Yoshiki Nakanish Hua-Yuan Zhang;Kazuhei Wakiya;Mitsuteru Nakamura;Masahito Yoshizawa;Yoshiki Nakanish(Graduate School of Science and Engineering,Iwate University,Morioka 020-8551,Japan)

机构地区：[1]Graduate School of Science and Engineering,Iwate University,Morioka 020-8551,Japan

出　　处：《Chinese Physics B》2024年第6期405-411,共7页中国物理B（英文版）

基　　金：Project supported by the Soft-Path Science and Engineering Research Center (SPERC),Iwate University;the JSPS KAKENHI (Grant Nos. JP18K03530,JP21K04622, and JP21K13869)。

摘　　要：We performed ultrasonic measurements on a quaternary cubic compound PrRu_(2)In_(2)Zn_(18) to explore the ground state properties derived from non-Kramers Γ_(3) doublet of Pr^(3+).PrRu_(2)In_(2)Zn_(18) is a quaternary derivative of the ternary compound PrRu_(2)Zn_(20) that exhibits a structural phase transition at T_S=138 K.In PrRu_(2)In_(2)Zn_(18),the Zn atoms at the 16c site in PrRu_(2)Zn_(20) are selectively replaced by In atoms.A monotonic increase was observed in the temperature dependence of elastic constants C_L=(C_(11)+2C_(12)+4C_(44))/3 and C_(T)=(C_(11)-C_(12)+C_(44))/3 in the temperature range around T_(S) to which an elastic softening was observed in(C_(11)-C_(12))/2 for PrRu_(2)Zn_(20).The disappearance of the softening indicates that the structural transition in PrRu_(2)Zn_(20) is suppressed by the substitution of Zn ions by In ones with a larger ionic radius.Alternatively,the C_(T) of PrRu_(2)In_(2)Zn_(18) exhibits a precursor Curie-type elastic softening toward low temperatures being responsible for the non-Kramers Γ_(3) ground state.We discuss the ground state and the evolution of the elastic properties of the different single-crystal samples of PrRu_(2)In_(2)Zn_(18) grown under different conditions.

关 键 词：ultrasonic measurements non-Kramers doublet structural phase transition crystalline electric field effect 

分 类 号：O469[理学—凝聚态物理]