La substitution effect on the magnetic phase transition of SmTi2Al20

TMU International Symposium on "New Quantum Phases Emerging from Novel Crystal Structure"

Higashinaka, Ryuji^1 ; Yamada, Akira^1 ; Matsuda, Tatsuma D.^1 ; Aoki, Yuji^1

Department of Physics, Tokyo Metropolitan University, 1-1, Minami-osawa, Tokyo, Hachioji

192-0397, Japan^1

关键词: Antiferromagnetic phase transition;    Concentration ranges;    Concentration values;    Heavy fermion compounds;    La substitutions;    Magnetic phase transitions;    Quantum critical points;    Self-flux methods;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/683/1/012018/pdf
DOI  :  10.1088/1742-6596/683/1/012018

来源: IOP

【 摘 要 】

Powder X-ray and specific heat measurements were performed on (SmxLa1-xTi2Al20(x = 0.2-1) single crystals grown by the Al self-flux method. All samples crystallize in the CeCr2Al20-type structure with Fd3m symmetry and the lattice parameter changes almost linearly with respect to the Sm concentration. From a λ-type peak appearing in the specific heat, it was found that the antiferromagnetic phase transition occurring at 6.5 K for x = 1 remains in the large Sm-concentration range. The transition temperature decreases almost linearly depending on the Sm concentration and goes to zero at the finite Sm concentration value of ∼ 0.1, indicating the possible existence of a quantum critical point. The robustness of the phase boundary against the magnetic field remains even in the La-substituted system. This behavior is in marked contrast to the field-sensitive behavior observed in Ce-based heavy fermion compounds.