Temperature dependence of magnetic properties and change of specific heat in perovskite ErCrO3 chromites

In this paper, the temperature dependence of magnetic properties and specific heat are systematically investigated for perovskite ErCrO3 chromites. The results show that there exists a strong temperature dependence of magnetic ordering and phase coexistence in the region of low temperature. Specifically, ErCrO3 possesses the long-range antiferromagnetic ordering and the appearance of weak ferromagnetism, occurring at TN =133 K. In the range of higher temperature, above 133.0 K, the reciprocal of magnetic susceptibility χ-1 behaves linearly, indicating a typical Curie-Weiss behavior fitted. The effective magnetic moment μ eff=10.57 μB and asymptotic paramagnetic Curie temperature Tcw=-30 K, which suggests the predominance of antiferromagnetic interactions in ErCrO3 chromites. Around TSR∼22 K, ErCrO3 undergoes a spin reorientation from Γ4(Gx,Ay,Fz;FRz) to Γ1(Ax,Gy,Cz;CRz) or Γ1(0). Also, the stability of the ferromagnetic Γ4 phase increases with increasing applied field. Furthermore, the ac susceptibilities exhibit frequency-independent anomalies near 133 K and the coexistence of the magnetic configuration Γ2(Fx,Gy,Cz;FRx,CRy) and Γ4. Combining the magnetic properties and the specific-heat measurements, this current magnetization can be interpreted from the interaction between Cr3+-Cr3+, Cr3+-Er3+ and Er3+-Er3+. (orig.)