INVESTIGADORES
BUSTINGORRY Sebastian
artículos
Título:
Second-order magnetic critical points at finite magnetic fields: Revisiting Arrott plots
Autor/es:
S. BUSTINGORRY; F. POMIRO; G. AURELIO; J. CURIALE
Revista:
PHYSICAL REVIEW B
Editorial:
American Physical Society
Referencias:
Año: 2016 vol. 93 p. 224429 - 224441
Resumen:
The so-called Arrott plot, which consists in plotting H/M against M^2, with H the applied magnetic field and M the magnetization, is used to extract valuable information in second-order magnetic phase transitions. Besides, it is widely accepted that a negative slope in the Arrott plot is indicative of a first-order magnetic transition. This is known as the Banerjee criterion. In consequence, the zero-field transition temperature T^∗ is reported as the characteristic first-order transition temperature. By carefully analyzing the mean-field Landau model used for studying first-order magnetic transitions, we show in this work that T^∗ corresponds in fact to a triple point where three first-order lines meet. More importantly, this analysis reveals the existence of two symmetricalsecond-order critical points at finite magnetic field (Tc,±Hc). We then show that a modified Arrott plot can be used to obtain information about these second-order critical points. To support this idea we analyze experimental data on La2/3Ca1/3MnO3 and discuss an estimate for the location of the triple point and the second-order critical points.