1/f noise properties of a La1-xCaxMnO3 thin film

Voltage noise studies of the La0.75Ca0.25MnO3 (LCMO) thin film in the low f requency region are presented. The observed noise arises due to the resista nce fluctuations and its magnitude fellows a power law of the 1/f form. The magnitude of the 1/f noise and the value of the Hooge's parameter in the p aramagnetic (PM) and ferromagnetic metallic states (FMM) are found to be mu ch larger than that of metals and semiconductors. The large magnitude of th e 1/f noise observed in the FMM state suggests that the contribution of str ong Jahn-Teller distortions is significant. Temperature dependence of the n ormalized noise shows a phase transformation from the PM state to FMM state . (C) 1998 Elsevier Science Ltd. All rights reserved.