Fresh Look at the Mystery of Magnetization Reversal in YVO3

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• 作者：Alexei A. Belik
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：August 5, 2013
• 年：2013
• 卷：52
• 期：15
• 页码：8529-8539
• 全文大小：655K
• 年卷期：v.52,no.15(August 5, 2013)
• ISSN：1520-510X

文摘

Phase transitions and detailed magnetic properties of polycrystalline AP-YVO_3.00(1) (prepared at ambient pressure by a conventional solid-state method) and polycrystalline HP-YVO_3.04(1) and HP-YVO_3.05(1) (AP-YVO₃ treated at 6 GPa and 1600 K during 130 and 15 min, respectively) were investigated. The three samples showed a remarkable exchange bias (EB) effect. HP-YVO_3.04 and HP-YVO_3.05 had similar chemical composition, crystallographic parameters, and particle size, but their magnetic properties were qualitatively different. EB was negative at all temperatures in AP-YVO₃ and HP-YVO_3.05, resulting in the absence of magnetization reversal (MR). Positive EB was observed in HP-YVO_3.04 between T_N2 = 71 K and T* = 88 K resulting in MR or negative magnetization between those temperatures. It was demonstrated that polycrystalline HP-YVO_3.04 behaved similar to single crystals of YVO_3+未. By the careful control of the trapped magnetic field, measurement conditions were found under which no MR occurred in HP-YVO_3.04 at moderate magnetic fields, indicating that MR is not an intrinsic property of YVO_3+未. A drastic effect of trapped magnetic fields on MR and memory effects were observed. The importance of an 鈥渋nsignificant鈥?anomaly at T_FM = 140 K for MR was suggested. We also suggested that 鈥減ositive exchange bias鈥? 鈥渄efects鈥? 鈥渋nterfaces鈥? and 鈥減inning鈥?should be keywords for understanding YVO₃ and probably other perovskite materials with the MR effect.