Relations between structural distortions and transport properties in Nd$_{0.5}$Ca$_{0.5}$MnO$_3$ strained thin films

TL;DR

This study investigates how structural distortions in strained Nd0.5Ca0.5MnO3 thin films affect their transport properties, revealing relationships between lattice changes and electronic behavior under different film thicknesses.

Contribution

It provides new insights into the correlation between structural distortions and transport properties in strained manganite thin films, highlighting the effects of film thickness and substrate-induced strain.

Findings

Thinner films show increased charge/orbital order transition temperatures.

Transport properties are significantly affected by substrate-induced strain.

Structural distortions influence bandwidth and Jahn-Teller effects.

Abstract

Strained thin films of charge/orbital ordered (CO/OO) $Nd_{0.5}Ca_{0.5}MnO_3$ (NCMO) with various thickness have grown on (100)-SrTiO$_3$ and (100)-LaAlO$_3$ substrates, by using the Pulsed Laser Deposition (PLD) technique. The thickness of the films influences drastically the transport properties. As the thickness decreases, the CO transition increases while at the same time the insulator-to-metal transition temperature decreases under application of a 7T magnetic field. Clear relationships between the structural distortions and the transport properties are established. They are explained on the basis of the elongation and the compression of the Mn-O-Mn and Mn-O bond angles and distances of the \QTR{it}{Pnma} structure, which modify the bandwidth and the Jahn-Teller distortion in these materials