Structural and Magnetic Investigations of Yb Substituted Y_1-xYb_xBaCo₄O₇ (0 ≤ x ≤ 0.5) Compound

Abstract

Structural and magnetic behavior of a series of new cobaltite Y_1-xYb_xBaCo₄O₇ (0 ≤ x ≤ 0.5), prepared using the conventional solid state reaction method have been investigated. Increasing Yb content leads to the increase in magnitude of magnetic moment and decreases the ferromagnetic transition (T_c) values. It is found that the predominant antiferromagnetic character of exchange interactions between cobalt ions, a ferromagnetic component, seemed to be strong enough to be detected still at room temperature. Our findings show that these materials exhibit ferromagnetic like transition at about T_c = 91 K, 80 K, 67 K, 55 K, 51 K and 45 K for composition x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5, respectively. We found that these materials exhibit spin-glass like state which dominates at low temperature.

Keywords:

• Cobaltite
• geometrical frustration
• solid-state reaction
• magnetic properties

Acknowledgments

The authors are thankful to Dr. Alok Banerjee (UGC, DAE, CSR Indore) to carry out the magnetization measurements.