Characterization of the charge order to ferromagnetic crossover behavior in (LayPr1-y)0.5Ca0.5MnO3

J.CURIALE; ...; PABLO EDUARDO LEVY; ET AL.

PHYSICA B - CONDENSED MATTER

Elsevier B.V.

Año: 2004 vol. 354 p. 1 - 1

0921-4526

Characterization of the charge order to ferromagnetic crossover behavior in (LayPr1-y)0.5Ca0.5MnO3 J. Curiale, C.A. Ramos, P. Levy, R.D. Sanchez, F. Rivadulla, J. Rivas We present structural and magnetization measurements in large-grain ceramic samples of the family (LayPr1-y)0.5Ca0.5MnO3 with y=0, 0.15, 0.3, 0.5, 0.7, 0.85 and 1.0. In this series, a change of the ionic radius in site A (rA) modi.es the structural parameters, which strongly affect the physical properties of these compounds. While the Ne´ el temperature remains essentially constant through the series, the ferromagnetic (FM) critical temperature (TC) decreases rapidly and the charge-order (CO) temperature (TCO) increases on decreasing y. The crossover of TC and TCO determines a critical tolerance factor (tcE0.975) consistent with previous reports on other systems with the same Mn3+/ Mn4+ ratio. For tolerance factors t near tc we observe coexistence of a FM and CO phases of varying degrees depending on y. For yp0:15 we .nd no evidence of ferromagnetism. 2004 Elsevier B.V. All rights reserved.