Conditions for the growth of smooth La0.7Sr0.3MnO3 thin films by pulsed electron ablation

TL;DR

This paper identifies optimal conditions for growing atomically flat La0.7Sr0.3MnO3 thin films using pulsed electron ablation, achieving smooth surfaces and robust magnetism suitable for spintronic applications.

Contribution

It demonstrates that increasing oxygen pressure and optimizing other parameters yields atomically flat, magnetic La0.7Sr0.3MnO3 films via Channel Spark Ablation.

Findings

Surface roughness reduced to unit cell size

Achieved magnetic films at 10-20 nm thickness

Optimal growth conditions identified

Abstract

We report on the optimisation of the growth conditions of manganite La0.7Sr0.3MnO3 (LSMO) thin films prepared by Channel Spark Ablation (CSA). CSA belongs to pulsed electron deposition methods and its energetic and deposition parameters are quite similar to those of pulsed laser deposition. The method has been already proven to provide manganite films with good magnetic properties, but the films were generally relatively rough (a few nm coarseness). Here we show that increasing the oxygen deposition pressure with respect to previously used regimes, reduces the surface roughness down to unit cell size while maintaining a robust magnetism. We analyse in detail the effect of other deposition parameters, like accelerating voltage, discharging energy, and temperature and provide on this basis a set of optimal conditions for the growth of atomically flat films. The thicknesses for which atomically flat surface was achieved is as high as about 10-20 nm, corresponding to films with room temperature magnetism. We believe such magnetic layers represent appealing and suitable electrodes for various spintronic devices.