DIRECT RELATIONSHIP BETWEEN MAGNETISM AND MNO6 DISTORTIONS IN LA1-XCAXMNO3

Measured distortions of the Mn-O bond length distribution from x-ray-a bsorption fine-structure measurements are found to relate linearly to the doped hole concentration x at room temperature in La1-xCaxMnO3. Co mparison of the distortions above and below T-c for colossal magnetore sistor (CMR) samples gives an estimate of the number of delocalized ho les n(dh), and we find that ln(n(dh)) proportional to M (magnetization ). These results are complementary to resistance measurements that sho w that ln(rho) proportional to -M. We have thus established the functi onal relationship between the electronic, spin, and lattice degrees of freedom in the CMR perovskites.