Magnetic ordered phase in La0.6Sr0.4MnO3 ferromagnets

L. B. STEREN ; M. SIRENA; J. GUIMPEL

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Año: 2002 vol. 65 p. 94431 - 94437

1098-0121

The ferromagnetic phase of La0.6Sr0.4MnO3 thin films has been investigated through measurements of magnetization loops at different temperatures, zero-field-cooled and field-cooled magnetization curves obtained under different magnetic fields. We have found that the main sources of the “bulk” coercivity in manganite films are the film/substrate interface and film surface. The temperature dependence of the coercivity is described by a “strong domain-wall pinning” model, independently of the thickness and substrate. The magnetization-vs-temperature curves, measured under different magnetic fields (10 Oe<H<2.5 kOe), have been explained in terms of the magnetic hysteresis of the films. We find no evidence of glass states or of the existence of single-domain clusters, as suggested by other authors.