Epitaxial thin films ofLa0.7Pb0.3MnO3have been grown on (100)LaAlO3and (110)SrTiO3substrates by dc magnetron sputtering. The magnetic-field and temperature-dependent resistivity of as-deposited and post-annealed films was examined. AtH=10 kOethe maximum observed magnetoresistance ratio(R0−RH)/R0was 62&percent;. The bolometric response to 0.94-&mgr;m low-frequency modulated radiation in the film with the temperature coefficient of resistanced ln R/dT=14&percent;was studied. The transport properties are described using Zhang’s spin-polaron theory. An unusual approach to stabilizing the film temperature at the point corresponding to the maximum of the magnetoresistance ratio and responsivity is discussed. ©1998 American Institute of Physics.