Linear expansion, phase separation, and magnetic inhomogeneities in La$_{0.92}$Ca$_{0.08}$MnO$_3$

A relation of the thermal expansion with magnetic and magnetotransport properties has been revealed in La$_{0.92}$Ca$_{0.08}$MnO$_3$ single crystals in the paramagnetic state. The magnetotransport and lattice properties and the specific features in the neutron scattering characteristics of the La$_{0.92}$Ca$_{0.08}$MnO$_3$ single crystals have been explained by the phase separation in the paramagnetic state into magnetic inhomogeneities (clusters) with short-range ($\sim$10 $\mathring{\mathrm{A}}$) and long-range ($>$ 10$^2$ $\mathring{\mathrm{A}}$) orders. The performed investigations have demonstrated that the clusters are closely related to the crystal lattice and that the magnetic inhomogeneities in the paramagnetic region are correlated to $T\sim$ 250–300 K $\gg T_C$.