Electrical resistivity in the ferromagnetic metallic state of La-Ca-MnO3:: Role of electron-phonon interaction

The temperature-dependent resistivity of the perovskite manganites La1-xCaxMnO3, With x = 0.33. is theoretically analysed within the framework of the classical electron-phonon model of resistivity. i.e.. the Bloch-Gruneisen model. Due to inherent acoustic (low-frequency) phonons (omega(ac)) as well as high-frequency optical phonons (omega(op)), the contributions to the resistivity have first been estimated. The acoustic phonons of the oxygen-breathing mode yield a relatively larger contribution to the resistivity compared to the contribution of optical phonons. Furthermore, the nature of phonons changes around T = 167 K exhibiting a crossover from an acoustic to optical phonon regime with elevated temperature. The contribution to resistivity estimated by considering both phonons, i.e. omega(ac) and omega(op), when subtracted from thin film data, infers a power temperature dependence over most of the temperature range. The quadratic temperature dependence of rho(diff). = [rho(exp.) - {rho(o) + rho(e-ph),(= rho(ac) + rho(op))}] is understood in terms of electron-electron scattering. Moreover, in the higher temperature limit, the difference can be varies linearly with T-4.5 in accordance with the electron-magnon scattering in the double exchange process. Within the proposed scheme; the present numerical analysis of temperature dependent resistivity shows similar results as those revealed by experiment.