Lieb-Mattis ferrimagnetic superstructure and superparamagnetism in Fe-based double perovskite multiferroics

Article

关键词: NEUTRON POWDER DIFFRACTION;    ROOM-TEMPERATURE;    RARE-EARTH;    SPIN-WAVES;    ORTHOFERRITES;    SUSCEPTIBILITIES;    SPECTROSCOPY;    FRUSTRATION;    SCATTERING;    EXCHANGE;   

DOI  :  10.1103/PhysRevB.90.134415

来源: SCIE

【 摘 要 】

We show an explicit mechanism of large superspin formation in double perovskites PbFe1/2M1/2O3 (M = Nb, Ta, and Sb). First, we demonstrate that antiferromagnetically interacting Fe3+ (S = 5/2) ions may be arranged in a periodic superstructure that exhibits a long-range ferrimagnetic ordering below T-fe approximate to 5.6J(1) (J(1)/k(B) similar to 50 K), which is close to room temperature. The ferrimagnetism of this superstructure is due to its geometry (so-called Lieb-Mattis ferrimagnetism), in contrast to the usual ferrimagnetism, which is due to the coupling of ions with different spin values. Next, we show that small clusters of the same structure exhibit a superparamagnetic behavior at T less than or similar to T-fe. The possibility of formation of such clusters explains the room-temperature (superpara) magnetism in 3d-metal based oxides.

【 授权许可】

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