title: Investigation of the magnetic properties in double perovskite R2CoMnO6 single crystals (R  =  rare earth: La to Lu).
abstract: We have successfully synthesized the series of the double-perovskite R2CoMnO6 (R  =  rare earth: La to Lu) single crystals and have investigated their magnetic properties. The ferromagnetic order of Co(2+)/Mn(4+) spins emerges mainly along the c axis. Upon decreasing the size of rare earth ion, the magnetic transition temperature decreases linearly from 204 K for La2CoMnO6 to 48 K for Lu2CoMnO6, along with the enhancement of monoclinic distortion. The temperature and magnetic-field dependences of magnetization reveal the various magnetic characteristics such as the metamagnetic transition in R  =  Eu, the isotropic nature of rare earth moment in R  =  Gd, and the reversal of magnetic anisotropy in R  =  Tb and Dy. Our results offer comprehensive information for understanding the roles of mixed-valent magnetic ions and rare earth magnetic moments on the magnetic properties.
authors.affiliation: Department of Physics and IPAP, Yonsei University, Seoul 120-749, Korea.
authors.forename: M K
authors.initials: MK
authors.lastname: Kim
authors.forename: J Y
authors.initials: JY
authors.lastname: Moon
authors.forename: H Y
authors.initials: HY
authors.lastname: Choi
authors.forename: S H
authors.initials: SH
authors.lastname: Oh
authors.forename: N
authors.initials: N
authors.lastname: Lee
authors.forename: Y J
authors.initials: YJ
authors.lastname: Choi