Exploring the substrate-driven morphological changes in Nd0.6Sr0.4MnO3 thin films

TL;DR

This study investigates how substrate-driven morphological changes in Nd0.6Sr0.4MnO3 thin films influence their structural and electrical properties, highlighting potential applications in oxide-based temperature sensors.

Contribution

It demonstrates the correlation between growth-induced nanostructures and enhanced electrical properties, introducing a method to tune thin film morphology for sensor applications.

Findings

Crossed-nano-rod morphology exhibits sharp MIT near room temperature.

Enhanced TCR up to ten times higher than granular films.

Morphology tuning improves potential for temperature sensing devices.

Abstract

Manganite thin films are promising candidates for studying the strongly correlated electron systems. Understanding the growth-and morphology-driven changes in the physical properties of manganite thin films is vital for their applications in oxitronics. This work reports the morphological, structural, and electrical transport properties of nanostructured Nd0.6Sr0.4MnO3 (NSMO) thin films fabricated using the pulsed laser deposition technique. Scanning electron microscopy (SEM) imaging of the thin films revealed two prominent surface morphologies: a granular and a unique crossed-nano-rod-type morphology. From X-ray diffraction (XRD) and atomic force microscopy (AFM) analysis, we found that the observed nanostructures resulted from altered growth modes occurring on the terraced substrate surface. Furthermore, investigations on the electrical-transport properties of thin films revealed that the films with crossed-nano-rod type morphology showed a sharp resistive transition near the metal-to-insulator transition (MIT). An enhanced temperature coefficient of resistance (TCR) of up to one order of magnitude was also observed compared to the films with granular morphology. Such enhancement in TCR % by tuning the morphology makes these thin films promising candidates for developing oxide-based temperature sensors and detectors.