Author:
Zhang 张 Hua-Yuan 化远,Wakiya Kazuhei,Nakamura Mitsuteru,Yoshizawa Masahito,Nakanish Yoshiki
Abstract
Abstract
We performed ultrasonic measurements on a quaternary cubic compound PrRu2In2Zn18 to explore the ground state properties derived from non-Kramers Γ3 doublet of Pr3+. PrRu2In2Zn18 is a quaternary derivative of the ternary compound PrRu2Zn20 that exhibits a structural phase transition at T
S = 138 K. In PrRu2In2Zn18, the Zn atoms at the 16c site in PrRu2Zn20 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 PrRu2Zn20. The disappearance of the softening indicates that the structural transition in PrRu2Zn20 is suppressed by the substitution of Zn ions by In ones with a larger ionic radius. Alternatively, the C
T of PrRu2In2Zn18 exhibits a precursor Curie-type elastic softening toward low temperatures being responsible for the non-Kramers Γ3 ground state. We discuss the ground state and the evolution of the elastic properties of the different single-crystal samples of PrRu2In2Zn18 grown under different conditions.