Stoichiometry, phase, and texture evolution in PLD-Grown hexagonal barium ferrite films as a function of laser process parameters

Abstract

Barium hexaferrite (BaFe12O19 or BaM) films were grown on c-plane sapphire (0001) substrates by pulsed laser deposition (PLD) to evaluate the effects of laser fluence on their composition, structure, and magnetic properties. A Continuum Surelite pulsed 266 nm Nd:YAG laser was employed, and the laser fluence was varied systemically between 1 and 5.7 [J/cm 2 ]. Deviations from the stoichiometric transfer between the BaM targets and deposited thin films occurred as the laser fluence changed. The Fe to Ba ratio in the films increased with laser fluence. The films deposited at laser fluences below 4 J/cm 2 showed undesirable 3-dimensional island growth.Moreover, insufficient laser energy resulted in the deposition of some secondary phases, for example, Barium monoferrite (BaFe2O4) and Magnetite (Fe3O4). Alternatively, laser fluences above 5 J/cm 2 promoted resputtering of the growing film at the substrate and degraded film quality, structure, and magnetic properties. BaM films deposited at 4.8 J/cm 2 -the optimal laser fluenceshowed excellent c-axis orientation perpendicular to the film plane with an anisotropy field of 16 kOe and saturation magnetization of 4.39 kG. These results clearly demonstrate a strong influence of laser parameters on PLD-grown hexaferrite films and provide a path for high-yield production using pulsed laser depositions systems.

Cation non-stoichiometry in Fe:SrTiO3 thin films and its effect on the electrical conductivity

“…Similar non-stoichiometries introduced by the PLD process are reported in literature for other materials as well [52][53][54][55][56][57][58][59][60][61][62].…”

Chalcogenide perovskite BaZrS3 thin-film electronic and optoelectronic devices by low temperature processing

“…PLD has been used to deposit a wide range of compounds including oxides, nitrides and carbides [35][36][37]. PLD is also known to be able to keep the stoichiometry of the target material under optimal conditions [38]. Postulating that by PLD deposition of a stoichiometric BaZrS3 compound target under optimal conditions, BaZrS3 perovskite thin films can be obtained under milder conditions.…”

Structure and Magnetization of Strontium Hexaferrite (SrFe12O19) Films Prepared by Pulsed Laser Deposition

“…Nowadays, investigators strive to determine deposition conditions that lead to improved performance. For example, deposition parameters that have been the foci of optimization studies include the choice of substrate (Hylton et al, 1993), substrate temperature (Xu et al, 2013a;Wei et al, 2020), working gas type and pressure , postdeposition annealing (Borisov et al, 2013), laser process conditions (Yu et al, 2020), and film thickness (Sun et al, 2016). Several common deposition techniques are available to obtain hexaferrite films of various crystallographic quality, including sol-gel , molecular beam epitaxy (MBE) (Liu et al, 2010), liquid phase epitaxy (LPE) (Kranov et al, 2006;Wu et al, 2020), screen printing (Chen et al, 2006), radio frequency (RF) magnetron sputtering (Zhang et al, 2010;Xu et al, 2013a;Patel et al, 2018;Abuzir et al, 2020), direct current (DC) magnetron sputtering (Zhang et al, 2014;Zhang et al, 2019), spin-coating (Meng et al, 2014a;Meng et al, 2014b), and pulsed laser deposition (PLD) (Eason, 2007).…”