Abstract
Investigation of structural and magnetotransport properties of (A=Ca,Sr) oxides reveals a gradual increase of the magnetic frustration with bending of the Mn-O-Mn bonds. The relative strength of competing magnetic interactions is controlled not only by [ is the mean radius of the ions at the (L, A) site] but also by the electronegativity of the divalent cation. The magnetoresistance of these oxides results mainly from spin disorder and the narrowing of the σ() band has only a minor effect. We have observed that the curve () is not universal but it is sensitive to the alkaline ions.
DOI:https://doi.org/10.1103/PhysRevB.55.R668
©1997 American Physical Society