文摘

Magnetic properties of Yb1?xCaxCrO3 with x = 0.0?.30 have been investigated in a temperature range of 3-00 K. The evidence of the existence of small trapped field (TF) resulting from trapped magnetic flux inside the superconducting material of physical property measurement system (PPMS) has been found during zero-field cooling mode. By using two measuring approaches, we have demonstrated that YbCrO3 has a strong dependence on the cooling field for the first time. Experimental results indicated that the magnetization configuration of YbCrO3 can memorizes the initial magnetic state induced by the cooling field and behaves according to it. Also, due to the strong anisotropic exchange interaction between Cr3+ and Yb3+, magnetic reversal and negative magnetization have been observed in YbCrO3.To investigate the interaction between Cr3+ and Yb3+, Ca-doped YbCrO3, which has been chosen as the studying object, were systematically investigated. X-ray diffraction patterns show that all the samples are in pure phase which can be indexed in orthorhombic structure belonging to space group Pbnm. DC magnetization measurements show that all compounds exhibit an antiferromagnetic transition at Néel temperature T N . Ca doping leads to a reduction of Cr3+–O2?/sup>–Cr3+ interactions due to the transformation of Cr3+ to higher oxidized state Cr4+. In addition, other interactions between Cr3+, Cr4+, and Yb3+ would appear in Ca-doped YbCrO3, which would also dilute the interactions of Cr3+–O2?/sup>–Cr3+.