Magnetic phase evolution in Fe substituted GdBaCo(2)O(5.5)

• Published in: Journal of magnetism and magnetic materials Vol. 322; no. 1; pp. 152 - 157
• Main Authors: Thirumurugan, N, Bharathi, A, Sundar, C S
• Format: Journal Article
• Language: English
• Published: 01.01.2010
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2009.09.007

Magnetization and magneto-resistance experiments have been carried out on well characterized samples of the GdBaCo(2-)(x))Fe(x)@O(5.5@ series. Zero field cooled magnetization measurements in the low concentration Fe samples suggest, that the low temperature anti-ferromagnetic phase transforms sequentially to several ferromagnetic phases, before transforming to a paramagnetic state with increase in temperature. The anti-ferromagnetic to the first ferromagnetic phase transition is associated with a large negative magneto-resistance for Fe fractions upto x=0.075. Isothermal magnetization measurements in the ferromagnetic like region of the samples, suggests the presence of mixtures of two ferromagnetic phases. Similar measurements performed at low temperatures where anti-ferromagnetic-like phase is stabilised suggest the presence of a mixture of anti-ferromagnetic and ferromagnetic phases. Magnetization and magneto- resistance are seen to collapse for Fe fractions, x > 0.1. Based on these studies a plausible scenario of the evolution of magnetism with Fe substitution in GdBaCo(2)O(5.5), is suggested.