# Anisotropic In-Plane Strain and Transport in Epitaxial Nd(0.2)Sr(0.8)MnO(3) Thin Films

## TL;DR

This study investigates how in-plane strain affects the structure and electrical transport properties of epitaxial Nd(0.2)Sr(0.8)MnO(3) thin films, revealing anisotropic strain effects and resistivity behavior across different film thicknesses.

## Contribution

It provides detailed analysis of strain-induced structural and electrical anisotropies in epitaxial Nd(0.2)Sr(0.8)MnO(3) films, highlighting the effects of tensile and compressive strains on their properties.

## Key findings

- Crystallographic c-axes remain fully strained across all thicknesses.
- Resistivity anisotropy increases exponentially with film thickness.
- Tensile strain enhances Neel temperature by approximately 25 K.

## Abstract

The structure, morphology, and electrical properties of epitaxial a-axis oriented thin films of Nd(0.2)Sr(0.8)MnO(3) are reported for thicknesses 10 nm <= t <= 150 nm. Films were grown with both tensile and compressive strain on various substrates. It is found that the elongated crystallographic c-axes of the films remain fully strained to the substrates for all thicknesses in both strain states. Relaxation of the a and b axes is observed for t>= 65 nm with films grown under tensile strain developing uniaxial crack arrays (running along the c axis) due to a highly anisotropic thermal expansion. For the latter films, the room-temperature in-plane electrical resistivity anisotropy, rho_b/rho_c, increases approximately exponentially with increasing film thickness to values of ~1000 in the thickest films studied. Films under tension have their Neel temperatures enhanced by ~25 K independent of thickness, consistent with an enhancement of ferromagnetic exchange along their expanded c axes.