Magnetic diffuse scattering of the $S$ = 5/2 fcc antiferromagnets Ba$_2$MnTeO$_6$ and Ba$_2$MnWO$_6$

Otto H. J. Mustonen; Charlotte E. Pughe; Lucile Mangin-Thro; Robert Tarver; Heather M. Mutch; Helen C. Walker; Edmund J. Cussen

paper

Magnetic diffuse scattering of the $S$ = 5/2 fcc antiferromagnets Ba $_{2}$ MnTeO $_{6}$ and Ba $_{2}$ MnWO $_{6}$

arXiv:2409.08323

Abstract

We have investigated the magnetic diffuse scattering of isostructural $S$ = 5/2 fcc antiferromagnets Ba $_{2}$ MnTeO $_{6}$ and Ba $_{2}$ MnWO $_{6}$ using polarized neutrons. Both materials display short-range correlated magnetism above their respective magnetic ordering temperatures of 20 K and 8 K. The spin correlations were analysed using a Reverse Monte Carlo approach. For Ba $_{2}$ MnTeO $_{6}$ , we find antiferromagnetic nearest-neighbor correlations along with ferromagnetic next-nearest neighbor correlations directly linked to the Type I order below $T_{N}$ . For Ba $_{2}$ MnWO $_{6}$ , both the nearest-neighbor and next-nearest-neighbor spin correlations are antiferromagnetic in the paramagnetic state. The short-range spin correlations persist up to $T$ = 7 $T_{N}$ . The magnetic diffuse scattering was also fitted using Onsager reaction-field theory allowing us to evaluate the magnetic interactions in these materials. We obtained $J_{1}$ = -3.25(3) K and $J_{2}$ = 0.41(2) K for Ba $_{2}$ MnTeO $_{6}$ and $J_{1}$ = -1.08(1) K and $J_{2}$ = -0.88(1) K for Ba $_{2}$ MnWO $_{6}$ . These interactions are comparable to previous results from inelastic neutron scattering experiments below $T_{N}$ , which highlights the potential of the Onsager approach for the analysis of magnetic interactions.

21+4 pages, 5+3 figures

Magnetic diffuse scattering of the S = 5/2 fcc antiferromagnets Ba2​MnTeO6​ and Ba2​MnWO6​

Abstract

Magnetic diffuse scattering of the $S$ = 5/2 fcc antiferromagnets Ba $_{2}$ MnTeO $_{6}$ and Ba $_{2}$ MnWO $_{6}$