Abstract
Double-exchange ferromagnets with their associated large magnetoresistance have recently been considered as candidates in magnetic storage applications. We review materials aspects of one compound family, La1-xCaxMnO3. There exist two distinct low temperature regimes; (i) ferromagnetic and metallic (x<0.5) and (ii) charge-ordered and semiconducting (x>0.5). We describe transport, magnetic, thermal and acoustic response in each regime. (C) 1997 American Institute of Physics.