Frustration effects in the disordered system CsMnFeF6, studied by neutron scattering, ac susceptibility, and magnetization measurements

摘要: In CsMnFe${\mathrm{F}}_{6}$, which has a cubic structure ($a=10.5$ \AA{}), space group $\mathrm{Fd}3m$, the magnetic ions ${\mathrm{Mn}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ form regular tetrahedra. The system should exhibit frustration effects, since nearest-neighbor interactions are antiferromagnetic in character. We performed neutron scattering, ac susceptibility, magnetization measurements both on powder single crystal, for temperatures $1.2\ensuremath{\le}T\ensuremath{\le}300$ K applied fields $0\ensuremath{\le}H\ensuremath{\le}50$ kOe. It was found that already at $T=300$ there well-developed clusters of antiferromagnetically coupled spins. These have weak resulting moment. Lowering temperature to $T\ensuremath{\simeq}80$ leads an increase effective moment due reduction thermal motions, whereas this remains constant $T\ensuremath{\lesssim}80$ K. At $T=26.3$ cluster moments freeze in\char22{}a process is accompanied by ferromagnetic ordering clusters. suggested field breaks large domains, containing many clusters, into microdomains only few or even one.