Ultrasonic Investigation of Magnetic Ordering with Higher-Order Interactions in the Cage-Structured Compound U3Pd20Si6

International Conference on Strongly Correlated Electron Systems 2014

Yanagisawa, Tatsuya^1 ; Hiura, Kenta^1 ; Mombetsu, Shota^1 ; Murazumi, Taro^1 ; Hidaka, Hiroyuki^1 ; Amitsuka, Hiroshi^1 ; Tateiwa, Naoyuki^2 ; Haga, Yoshinori^2

Graduate School of Science, Hokkaido University, Sapporo

060-0810, Japan^1

Advanced Science Research Center, Japan Atomic Energy Agency, Tokai

319-1195, Japan^2

关键词: Elastic properties;    Electric quadrupoles;    Local charge distributions;    Lower temperatures;    Magnetoelastic couplings;    Ultrasonic attenuation;    Ultrasonic investigations;    Zero magnetic fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012095/pdf
DOI  :  10.1088/1742-6596/592/1/012095

来源: IOP

【 摘 要 】

The elastic properties of localized 5f-electron system U3Pd20Si6were studied by means of ultrasonic measurements under magnetic fields. We have measured elastic constants C11, (C11-C12)/2, C44and CL110= CB+ (C11-C12)/6 + C44in order to check a possible contribution of electric quadrupoles on the magnetically ordered phases of this compound for Γ1⊕ Γ3, Γ3, Γ5and Γ1⊕ Γ3⊕ Γ5symmetries elastic response, respectively. We discovered that an elastic anomaly, which is accompanied by ultrasonic attenuation maximum of Γ5- symmetry mode, at around T∗∼ 16 K in zero magnetic field and shifts to lower temperatures with increasing magnetic fields. Since the T∗seems to be continuously connected to the lower boundary of a 'spin-flop' region in the magnetic field-temperature phase diagram of U3Pd20Si6, we conclude that a fluctuation of the spin-system of the 8c-site ion exists even just below TNand couples to elastic wave via magneto-elastic coupling with Γ5-symmetry quadrupoles of U's 5f electron or local charge distributions of the guest U ion.