Temperature and Ag doping effect on magnetic excitations in the quasi-two-dimensional triangular lattice antiferromagnet CuCrO studied by inelastic neutron scattering

擬二次元三角格子反強磁性体CuCrOの磁気励起に対する温度及びAg置換効果の非弾性中性子散乱による研究

梶本 亮一  ; 中島 健次  ; 河村 聖子   ; 稲村 泰弘; 加倉井 和久; 新井 正敏; 外園 貴久*; 大園 怜*; 奥田 哲治*

Kajimoto, Ryoichi; Nakajima, Kenji; Kawamura, Seiko; Inamura, Yasuhiro; Kakurai, Kazuhisa; Arai, Masatoshi; Hokazono, Takahisa*; Ozono, Akira*; Okuda, Tetsuji*

We have studied magnetic excitations in quasi two-dimensional triangular lattice antiferromagnets CuCrO and CuAgCrO by inelastic neutron scattering. CuCrO has two types of magnetic excitations: the one is highly dispersive, while the other is less dispersive and spreads over a wide range. With increasing the temperature, the weight of the latter component transfers to a lower energy, and the spin dynamics becomes a mixture of disordered spin wave and another diffusive component. The Ag doping induces similar spin dynamics even at 5 K. This manifests the impact of the Ag doping on the magnetic correlations and gives a clue to understand the unconventional spin state in the Ag doped CuCrO.