Suppression of ferromagnetism in La3CrAs5 via V substitution

In this work, we successfully synthesized a series of hexagonal La ₃Cr _{1- x}V _xAs ₅ ( x = 0–0.8) polycrystalline samples under high-temperature and high-pressure conditions. A systematic study was carried out via the measurements of X-ray powder diffraction, temperature- and field-dependent magnetic susceptibility and magnetization. The X-ray diffraction data show that the lattice constant. a-parameter gradually increases, while c-parameter decreases with increasing V-doping level. In this series, the ferromagnetic behavior has been observed for x ≤ 0.3, and the Curie temperature T _C decreases from 50 K for the parent compound to 20 K for x = 0.3, which indicates that the ferromagnetism is suppressed as the V-doped increases. For x = 0.4, the system begins to enter into a new magnetic state like spin glass at low temperature, and no magnetic order can be observed down to 2 K for x ≥ 0.8. In addition, the Weiss temperature T_ϴ gradually decreases and changes to be negative for x = 0.6, which suggests that ferromagnetic interaction at first is weakened by the V substitution, and then transforms into anti-magnetic predominant interaction. The above results indicate that there is no quantum criticality occurred in the La ₃Cr _{1- x}V _xAs ₅ system.