Eur. Phys. J. B 15, 461-468 (2000)
https://doi.org/10.1007/s100510051147

Influence of high-energy electron irradiation on the transport properties of La_1-xCa_xMnO₃)

¹ B. Verkin Institute for Low Temperature Physics & Engineering, Kharkov, 310164, Ukraine
² Kharkov State University, Kharkov, 310077, Ukraine
³ Department of Physics, Texas A& M University, College Station, TX 77843-4242, USA

Received: 21 July 1999
Revised: 27 December 1999
Published online: 15 June 2000

Abstract

The effect of crystal lattice disorder on the conductivity and colossal magnetoresistance in LaCa_xMnO₃ () films has been examined. The lattice defects are introduced by irradiating the film with high-energy ( MeV) electrons with a maximal fluence of about cm^-2. This comparatively low dose of irradiation produces rather small radiation damage in the films. The number of displacements per atom (dpa) in the irradiated sample is about 10^-5. Nevertheless, this results in an appreciable increase in the film resistivity. The percentage of the resistivity increase in the ferromagnetic metallic state (below the Curie temperature T_c) was much greater than that observed in the insulating state (above T_c). At the same time irradiation has much less effect on T_c or on the magnitude of the colossal magnetoresistance. A possible explanation of such behavior is proposed.