Anisotropy in magnetic and transport properties ofLaTSb3(T=Cr,V)

We report measurements of anisotropy in magnetic susceptibility, magnetization, and electrical resistivity using single crystals of $\mathrm{La}T{\mathrm{Sb}}_3$ $(T=\mathrm{Cr},\mathrm{V}).\mathrm{}$ $\mathrm{La}T{\mathrm{Sb}}_3$ is a quasi-two-dimensional system with an orthorhombic crystal structure (space group $Pbcm),$ possessing a rich phase diagram with a ferromagnetic transition at $T_C=132\mathrm{}\hspace{0.5em}\mathrm{K}$ due to the ordering of the Cr ions. In order to investigate $\mathrm{La}T{\mathrm{Sb}}_3,$ magnetic susceptibility and magnetization for fields up to 55 kG and in the temperature range of 2–350 K have been measured with the field aligned to the three principle axes. The electrical resistivity of ${\mathrm{LaCrSb}}_3$ has been measured for currents parallel to the a, b, and c axes in the temperature range 5–295 K, as well as magnetoresistances at 20 k and 60 kG along the b axis. Isostructural ${\mathrm{LaVSb}}_3$ is found have no transitions in either the magnetization or the resistivity; therefore, it is presented as a nonmagnetic counterpart. Just below $T_C,$ the easy axis is found to be within the $b-c$ plane in the direction of the magnetic field. As the system is further cooled, there is a crossover from quasi-two-dimensional (2D) to 3D anisotropy below a characteristic temperature $T^{*},$ and the easy axis of magnetization becomes oriented along the b axis. Furthermore, it is found that $T^{*}$ decreases linearly as the magnetic field is increased, and is suppressed with a field $H>\mathrm{}3.7\mathrm{}\hspace{0.5em}\mathrm{kG}.$ A high-temperature antiferromagnetic transition is found at $T_N=98\mathrm{}\hspace{0.5em}\mathrm{K}.$ The value of $T_N$ is found to be independent of the applied magnetic field up to $H=0.25\mathrm{}\hspace{0.5em}\mathrm{kG},$ at which point this antiferromagnetic phase is suppressed.