High temperature electronic behavior of La0.8Sr0.2MnO3 thin film

TL;DR

This study investigates the high-temperature electronic behavior of La0.8Sr0.2MnO3 thin films, revealing a discontinuous metal-semiconductor transition and temperature-dependent shifts in electronic states due to lattice effects.

Contribution

It provides new insights into the temperature-induced electronic structure changes and phase transition characteristics of La0.8Sr0.2MnO3 thin films prepared by Laser MBE.

Findings

Discontinuous variation indicating a metal-semiconductor transition between 350 K and 450 K.

Upward shift of core level and valence-band binding energies at high temperatures.

Narrowing of spectral line-widths attributed to lattice expansion and Jahn-Teller distortion.

Abstract

The electronic structure of La0.8Sr0..2MnO3/SrTiO thin film, which was prepared by Laser MBE, was studied by X-ray photoemission spectra (XPS) in the temperature interval of 300 to 1000 K. Experimental results showed that the electronic state of the thin film underwent a discontinuous variation between 350 K and 450 K, indicating that the metal-semiconductor transition was probably a discontinuous phase transition. At high temperature (450 to 1000 K), both the binding energies of the atomic core level and valence-band of the film shifted up with increasing the temperature, while their line-widths became narrower, which were different from that observed at low temperature. These phenomena are attributed to the crystal lattice expansion and related Jahn-Teller distortion varying with temperature.