Magnetic and charge ordering properties of Bi0.6-x(RE)xCa0.4MnO3 (0.0 ≤ x ≤ 0.6) perovskite manganites

Abstract

In this work, we studied structural, magnetic, and charge ordering properties of polycrystalline Bi0.6−x (RE)x Ca0.4MnO3 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6) samples, synthesized via solid state reaction route and by taking RE = La, Pr, and Nd, separately. The temperature dependence magnetization measurement reveals that the x = 0.0 compound (BCMO) exhibits a charge ordered (CO) and antiferromagnetic (AFM) phase with the charge ordering temperature (TCO) ∼289 K and the antiferromagnetic ordering temperature (TN) ∼136 K. Only a small fraction of La-dopant in BCMO is sufficient to destroy the CO completely, whereas a large concentration of La (viz., x = 0.2 to x = 0.6) promotes ultimately a paramagnetic to ferromagnetic (PM-FM) transition, and the PM-FM transition temperature (TC) decreases progressively from 241 K to 203 K as x increases from 0.2 to 0.5. In contrast, systematic substitution of Pr or Nd at Bi site induces an intriguing interplay between the charge ordering and antiferromagnetism. Our results demonstrate that the value of TCO decreases with increasing value of “x” and the value of TN increases sharply at both the extremes; however, it remains nearly constant from x = 0.2 to 0.4. In our samples, a glassy magnetic states are also observed at far below the TN.