High-quality NiFe thin films on oxide/non-oxide platforms via pulsed laser deposition at room temperature

TL;DR

This study demonstrates the successful growth of high-quality NiFe ferromagnetic thin films on various substrates using pulsed laser deposition at room temperature, with properties tunable by laser fluence and substrate surface quality.

Contribution

It presents a novel method for depositing high-quality NiFe films via PLD at room temperature, highlighting the influence of laser fluence and substrate surface on magnetic properties.

Findings

Optimal laser fluence of 4 J/cm$^2$ yields highest magnetization (~547 emu/cc)

Films exhibit low coercivity and uniaxial in-plane anisotropy

Magnetic properties are sensitive to substrate surface quality

Abstract

Soft ferromagnetic NiFe thin films are promising for applications in spintronic devices because of their constituent electrical and magnetic properties. Electron beam evaporation and sputtering techniques have been used to deposit NiFe thin films. For in-situ stacking of NiFe with functional complex oxides, the pulsed laser deposition (PLD) method is highly desirable. However, the growth of high-quality NiFe (and non-oxide thin films in general) by PLD remains a formidable task. Here, we report high-quality NiFe thin films of various thicknesses on oxide/non-oxide substrates with desirable magnetic properties by PLD at room temperature. The magnetic properties are found to be strongly dependent on the laser fluence of the deposition process. The laser fluence of 4 Joule/cm$^2$ produces the highest magnetization of ~547 emu/cc. The small coercivity (few Oersted) and sharp ferromagnetic switching behaviour indicate uniaxial anisotropy with an easy axis along the in-plane direction. In addition, thickness-dependent magnetodynamics characterizations are studied via ferromagnetic resonance. Our findings indicate the ferromagnetic characteristics are sensitive to the quality of the oxide/non-oxide substrate surface. These results offer significant insight into the PLD-based development of thin metal magnetic films.