Nonmagnetic impurity effect on magnetic correlation in the triangular-lattice antiferromagnet Ba₃Mn_1−xZn_xSb₂O₉(0 < x < 0.16)

¹ School of Physics & Electronic Engineering, Zhengzhou University of Light Industry - Zhengzhou, 450002, PRC
² School of Physics and Wuhan National Pulsed High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, PRC
³ High Magnetic Field Laboratory, Chinese Academy of Science - Hefei 230031, PRC
⁴ School of Physics, Wuhan University - Wuhan 430072, PRC

^(a) tianzhaoming@hust.edu.cn

Received: 18 April 2018
Accepted: 16 October 2018

Abstract

The nonmagnetic impurity effects on the triangular-lattice antiferromagnet (TLAF) Ba₃Mn_1−xZn_xSb₂O₉ () by Zn²⁺ () dilutions are investigated based on magnetic susceptibility, specific heat and electron spin resonance (ESR) measurements. The ac susceptibility and specific heat result reveal that the two-dimensional (2D) antiferromagnetic (AFM) ground state is stable rather than forming a spin-glass (SG) phase for Zn²⁺ substitution up to , where the AFM transition temperature (T_N) shifts slowly from 10.2 K () to 8.2 K (). For all samples, the divergence of the temperature-dependent linewidth of ESR can be well described in terms of the Berezinskii-Kosterlitz-Thouless (BKT) scenario. The evolution of ESR spectra suggests that the nonmagnetic impurity does not induce magnetic defects decoupled with AFM matrix but rather change the bulk AFM properties.