Abstract:
Weakly mechanically stressed 40-nm-thick La$_{0.67}$Ca$_{0.33}$MnO$_3$ films have been grown coherently on a (001)NdGaO$_3$ substrate by laser evaporation. The electrical resistivity $\rho$ of the La$_{0.67}$Ca$_{0.33}$MnO$_3$ film reaches a maximum at a temperature $T_C\approx$ 255 K. At temperatures below 0.6$T_C$, the temperature dependences of $\rho$ are well approximated by the relation $\rho=\rho_{\mathrm{def}}+C_1T^2+C_2T^{4.5}$, in which the first term on the right-hand side accounts for the contribution of structural defects to electrical resistivity, and the second and third terms stand for those of the electron-electron and electron-magnon interactions, respectively. The parameters $\rho_{\mathrm{def}}\approx$ 1 $\times$ 10$^{-4}$$\Omega$ cm and $C_1\approx$ 7.7 $\times$ 10$^{-9}$$\Omega$ cm K$^{-2}$ do not depend on temperature and magnetic field $H$. The coefficient $C_2$ decreases with increasing $H$ to reach about 4.9 $\times$ 10$^{-15}$$\Omega$ cm K$^{-4.5}$ at $\mu_0 H$ = 14 T.