Magnetization and magnetodielectric effect in Cr3+-doped Ca3Co2-xCrxO6 compounds.

In one dimensional Ca 3 Co 2 O 6 , the magnetic frustration could result in partially disordered antiferromagnetic state. The Ca 3 Co 2 O 6 thus presents spin freezing and slow relaxation at low temperature. In this investigation, magnetic Cr3+-dopants were chosen to substitute the Co3+ cations and a series of Ca 3 Co 2- x Cr x O 6 ceramics were synthesized. Their magnetoelectric properties were characterized. The results manifest that the introduced Cr3+ cations situate in the CoO 6 octahedral centers and they could increase the lattice volume slightly. The antiferromagnetic coupling between Cr3+ and the adjacent Co3+ could reduce the frustration. The doped-Ca 3 Co 2- x Cr x O 6 compounds display a slower magnetic dynamic behavior. The Cr3+ substitution also has great impact on the dielectric properties of Ca 3 Co 2 O 6. The slower response of the freezing spin in Cr3+ doped-Ca 3 Co 2 O 6 makes the dielectric anomaly (anomaly Ⅰ) around the freezing temperature weakens with increasing Cr3+. Additionally, the introduced Cr3+ dopant not only increases the dielectric permittivity but also decreases the dielectric loss greatly. Cr3+ cation is a good candidate for improving the dielectric properties of Ca 3 Co 2 O 6. Magnetodielectric measurement reflects the effectiveness of magnetic field on manipulating the electric dipole of Ca 3 Co 2 O 6. For spin frustrated materials, electric measurement is proved to be an effective method on characterizing the subtle variation of the magnetic structure. [ABSTRACT FROM AUTHOR]