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Critical properties of the double exchange ferromagnet Nd0.4Pb0.4MnO3

M. Sahana·U. K. Roessler·Nilotpal Ghosh·Suja Elizabeth·H. L. Bhat·K. Doerr·D. Eckert·M. Wolf·K. -H. Mueller
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Abstract

Results of a study of dc-magnetization M(T, H), performed on a Nd0.6Pb0.4MnO3 single crystal in the temperature range around T_C (Curie temperature) which embraces the critical region | epsilon | = |T -T_C |/T_C <= 0.05 are reported. The magnetic data analyzed in the critical region using the Kouvel-Fisher method give the values for the T_C =156.47 +/- 0.06 K and the critical exponents, beta = 0.374 +/- 0.006 (from the temperature dependence of magnetization), and gamma = 1.329 +/- 0.003 (from the temperature dependence of initial susceptibility). The critical isotherm M(T_C, H) gives delta = 4.547 +/- 0.1. Thus the scaling law gamma+beta=delta beta is fulfilled. The critical exponents obey the single scaling-equation of state M(H, epsilon) = epsilon^b f_+/- (H/epsilon^(beta + gamma)) where, f_+ for T > T_C and f_- for T< T_C. The exponent values are very close to those expected for the universality class of 3D Heisenberg ferromagnets with short-range interactions.

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M. Sahana, U. K. Roessler, Nilotpal Ghosh, Suja Elizabeth, H. L. Bhat, K. Doerr, D. Eckert, M. Wolf, K. -H. Mueller. 2003-04-02. Critical properties of the double exchange ferromagnet Nd0.4Pb0.4MnO3. https://doi.org/10.1103/physrevb.68.144408

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