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Title: Effect of Growth Temperature on the Magnetic, Microwave, and Cation Inversion Properties on NiFe2O4 Thin Films Deposited by Pulsed Laser Ablation Deposition

Abstract

First principles band structure calculations suggest that the preferential occupation of Ni{sup 2+} ions on the tetrahedral sites in NiFe{sub 2}O{sub 4} would lead to an enhancement of the exchange integral and subsequently the Neel temperature and magnetization. To this end, we have deposited NiFe{sub 2}O{sub 4} films on MgO substrates by pulsed laser deposition. The substrate temperature was varied from 700 to 900 {sup o}C at 5 mTorr of O2 pressure. The films were annealed at 1000 {sup o}C for different times prior to their characterization. X-ray diffraction spectra showed either (100) or (111) orientation with the spinel structure dependent on the substrate orientation. Magnetic studies showed a magnetization value of 2.7 kG at 300 K. The magnetic moment was increased to the bulk value as a result of postdeposition annealing at 1000 {sup o}C. The as produced films show that the ferromagnetic resonance linewidth at 9.61 GHz was 1.5 kOe, and it was reduced to 0.34 kOe after postannealing at 1000 {sup o}C. This suggests that the annealing led to the redistribution of Ni{sup 2+} ions to their equilibrium octahedral sites. Further, it is shown that the magnetically preferred direction of H{sub a} can be aligned perpendicular tomore » the film plane when films are grown with a fixed oxygen pressure of 5 mTorr for films deposited at 700 and 900 {sup o}C.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
930513
Report Number(s):
BNL-80483-2008-JA
Journal ID: ISSN 0021-8979; JAPIAU; TRN: US200904%%567
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 101
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; NICKEL OXIDES; IRON OXIDES; DEPOSITION; SUBSTRATES; MAGNESIUM OXIDES; TEMPERATURE DEPENDENCE; MAGNETIZATION; MAGNETIC MOMENTS; ELECTRONIC STRUCTURE; national synchrotron light source

Citation Formats

Chinnasamy,C., Yoon, S., Yang, A., Baraskar, A., Vittoria, C., and Harris, V.. Effect of Growth Temperature on the Magnetic, Microwave, and Cation Inversion Properties on NiFe2O4 Thin Films Deposited by Pulsed Laser Ablation Deposition. United States: N. p., 2007. Web. doi:10.1063/1.2714204.
Chinnasamy,C., Yoon, S., Yang, A., Baraskar, A., Vittoria, C., & Harris, V.. Effect of Growth Temperature on the Magnetic, Microwave, and Cation Inversion Properties on NiFe2O4 Thin Films Deposited by Pulsed Laser Ablation Deposition. United States. doi:10.1063/1.2714204.
Chinnasamy,C., Yoon, S., Yang, A., Baraskar, A., Vittoria, C., and Harris, V.. Mon . "Effect of Growth Temperature on the Magnetic, Microwave, and Cation Inversion Properties on NiFe2O4 Thin Films Deposited by Pulsed Laser Ablation Deposition". United States. doi:10.1063/1.2714204.
@article{osti_930513,
title = {Effect of Growth Temperature on the Magnetic, Microwave, and Cation Inversion Properties on NiFe2O4 Thin Films Deposited by Pulsed Laser Ablation Deposition},
author = {Chinnasamy,C. and Yoon, S. and Yang, A. and Baraskar, A. and Vittoria, C. and Harris, V.},
abstractNote = {First principles band structure calculations suggest that the preferential occupation of Ni{sup 2+} ions on the tetrahedral sites in NiFe{sub 2}O{sub 4} would lead to an enhancement of the exchange integral and subsequently the Neel temperature and magnetization. To this end, we have deposited NiFe{sub 2}O{sub 4} films on MgO substrates by pulsed laser deposition. The substrate temperature was varied from 700 to 900 {sup o}C at 5 mTorr of O2 pressure. The films were annealed at 1000 {sup o}C for different times prior to their characterization. X-ray diffraction spectra showed either (100) or (111) orientation with the spinel structure dependent on the substrate orientation. Magnetic studies showed a magnetization value of 2.7 kG at 300 K. The magnetic moment was increased to the bulk value as a result of postdeposition annealing at 1000 {sup o}C. The as produced films show that the ferromagnetic resonance linewidth at 9.61 GHz was 1.5 kOe, and it was reduced to 0.34 kOe after postannealing at 1000 {sup o}C. This suggests that the annealing led to the redistribution of Ni{sup 2+} ions to their equilibrium octahedral sites. Further, it is shown that the magnetically preferred direction of H{sub a} can be aligned perpendicular to the film plane when films are grown with a fixed oxygen pressure of 5 mTorr for films deposited at 700 and 900 {sup o}C.},
doi = {10.1063/1.2714204},
journal = {Journal of Applied Physics},
number = ,
volume = 101,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Silk fibroin is a simple protein expected to have functional applications in medicine and bioelectronics. The primary structure of this protein is quite simple, and the main secondary structures are {beta}-sheet crystals and amorphous random coils. In the present study, we investigated pulsed laser deposition (PLD) of fibroin with the {beta}-sheet structures as targets. The primary and secondary structures in films deposited were analyzed using infrared spectroscopy. Normal laser deposition at 351 nm using neat fibroin targets produced thin films of fibroin with a random coiled structure. Ablation was triggered by two-photonic excitation of the peptide chains, which resulted inmore » the destruction of {beta}-sheet structure in PLD. In order to avoid the two-photonic excitation, we adopted a PLD method utilizing anthracene (5{endash}0.1 wt%) in a photosensitized reaction involving doped fibroin targets. Laser light (351 or 355 nm) was absorbed only by anthracene, which plays an important role converting photon energy to thermal energy with great ablation efficiency. Thin fibroin films deposited by this method had both random coil and {beta}-sheet structures. As the dopant concentration and laser fluence decreased, the ratio of {beta}-sheet domain to random coil increased in thin deposited films. {copyright} 2001 American Institute of Physics.« less
  • Conductive RuO{sub 2} thin films were grown on different substrates by pulsed laser deposition. Films deposited on MgO are of (110) orientation and of polycrystalline nature, while highly crystalline RuO{sub 2} films can be heteroepitaxially grown on LaAlO{sub 3} and yttria-stabilized zirconia (YSZ) substrates under proper processing conditions. The crystalline RuO{sub 2} thin films show metallic resistivity versus temperature characteristics and have a room-temperature resistivity of 35{plus_minus}2 {mu}{Omega}cm. A residual resistivity ratio ({rho}{sub 300 K}/{rho}{sub 4.2 K}) of around 5 has been achieved for the RuO{sub 2} thin films grown at a substrate temperature of 700{degree}C on both LaAlO{sub 3}more » and YSZ. {copyright} {ital 1996 American Vacuum Society}« less
  • We have successfully grown epitaxial CoFe{sub 2}O{sub 4} (CFO) thin film on SrTiO{sub 3} by metal organic chemical vapor deposition. In order to understand the surface structure and its correlation with magnetic properties, CFO thin films were deposited at a range of deposition temperatures. As the deposition temperature is decreased, a huge effect on film morphology and surface roughness is observed, resulting from a change in the size and density of the crystal nuclei. These changes to grain structure and surface roughness modify the energy landscape of the films and are major contributors to the change in magnetic properties asmore » a function of deposition temperature: the direction of the easy axis is aligned in-plane at lower deposition temperatures and lower anisotropy between different directions is observed in the rough films grown at high temperature.« less
  • In this paper the authors report results on the growth of borocarbides ErNi{sub 2}B{sub 2}C and DyNi{sub 2}B{sub 2}C thin films by an ultra high vacuum laser ablation technique. The dependence of the film structure and properties on the deposition parameters has been studied. Moreover the possibility to obtain superconducting films with a tungsten buffer layer on MgO substrates has been successfully checked. Here the authors present details on the deposition procedure as well as on the structural, morphological, and physical characterization.
  • In the pulsed laser deposition of thin films, plasma parameters such as energy and density of ions play an important role in the properties of materials. In the present work, cadmium telluride thin films were obtained by laser ablation of a stoichiometric CdTe target in vacuum, using two different values for: substrate temperature (RT and 200 °C) and plasma energy (120 and 200 eV). Structural characterization revealed that the crystalline phase can be changed by controlling both plasma energy and substrate temperature; which affects the corresponding band gap energy. All the thin films showed smooth surfaces and a Te rich composition.