Tuning Magnetism by Excessive Cr in Cr$_{\mathrm{1+}}_{x}$Te$_{\mathrm{2}}$ Single Crystals*

Layered transition-metal dichalcogenides exhibit various interesting electronic and magnetic properties. CrTe$_{\mathrm{2}}$ is one of such compounds that is a ferromagnetic (FM) metal below 310 K. We report experimental investigations on the electrical transport and magnetic properties of single-crystalline Cr$_{\mathrm{1+}}_{x}$Te$_{\mathrm{2}}$ with the extra Cr($x=$ 0.16, 0.23) located between the CrTe$_{\mathrm{2}}$ layers. Measurements of magnetization along both the \textit{ab}-plane and $c$-axis indicate that the insertion of Cr between layers switches the easy FM direction from the \textit{ab}-plane to the $c$-axis and lowers Curie temperature, $T_{C}$, when compared to the stoichiometric case ($x=$ 0). Interestingly, both $T_{C\thinspace }$and the electrical conductivity increase with increasing $x$, suggesting a variation of the electronic structure with $x$. This is further confirmed by the low-temperature specific heat, which reveals a larger electronic contribution at higher $x$