Center for Correlated Electron Systems

Seminar

Intriguing Magnetic Properties of Double Perovskite R2CoMnO6 Single Crystals (R=La, Gd, and Er)

April 25, 2018l Hit 644
Date : January 24, 2018 15:00 ~ 16:30
Speaker : Dr. Mi Kyung Kim(Yonsei Univ)
Location : Bldg. 19, Rm. 210

Exploring new magnetic materials is essential for finding advantageous functional properties such as magnetoresistance, magnetocaloric effect, spintronic functionality, and multiferroicity. Versatile classes of double perovskite compounds have been recently investigated because of intriguing physical properties arising from the proper combination of several magnetic ions. Rod-shaped single crystals of highly-ordered double perovskites R2CoMnO6 (R=rare earth: La to Lu) with the typical size of 2 2 5 mm3 were grown by the conventional flux method with Bi2O3 flux. The superexchange interaction between Co2+ (high spin, S=3/2) and Mn4+ (S=3/2) ions via an oxygen leads to the long-range ferromagnetic order in La2CoMnO6 single crystal, mainly along the c axis. Gd2CoMnO6 single crystal exhibits giant anisotropic magnetocaloric effect. In Er2CoMnO6 single crystal, the inverted magnetic hysteresis loop observed below TComp can be described by an extended Stoner Wohlfarth model that is established from contrasting magnetic anisotropy and moments between Er3+ and ferromagnetic Co2+/Mn4+ sublattices. Moreover, the coexisting ferrimagnetic and multiferroic phases of Er2CoMnO6 appear to be strongly correlated in that metamagnetic and dielectric transitions occur simultaneously. Our results based on intricate magnetic correlations and phases in R2CoMnO6 (R=La, Gd, and Er) enrich fundamental and applied research on magnetic materials through the scope of distinct magnetic characteristics in double perovskites.

 

Host: Prof. Changyoung Kim