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Title: Investigation of phase transformation behavior in sputter deposited PtMn thin films

Abstract

Sputter-deposited, equiatomic PtMn thin films have application in giant magnetoresistive spin valves, tunneling magnetoresistive spin valves, and magnetic random access memory. However, the as-deposited films are found to be a disordered A1 phase in a paramagnetic state rather than an antiferromagnetic phase with L1{sub 0} structure, which is needed for device operation. Therefore, a postannealing step is required to induce the phase transformation from the as-deposited A1 face-centered-cubic phase to the antiferromagnetic L1{sub 0} phase. The A1 to L1{sub 0} metastable transformation was studied by x-ray diffraction and differential-scanning calorimetry. An exothermic transformation enthalpy of -12.1 kJ/mol of atoms was determined. The transformation kinetics were simulated using the Johnson-Mehl-Avrami analysis.

Authors:
 [1];  [2];  [3];  [4];  [1];  [1];  [5];  [5];  [5]
  1. University of Wisconsin, Madison
  2. Hutchinson Technology, Hutchinson, MN
  3. ORNL
  4. CompuTherm LLC, Madison, WI
  5. Seagate Technology, Bloomington, MN
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Laboratory Directed Research and Development (LDRD) Program
OSTI Identifier:
978162
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the Minerals Metals & Materials Society (JOM); Journal Volume: 58; Journal Issue: 6
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ATOMS; CALORIMETRY; ENTHALPY; FCC LATTICES; KINETICS; PHASE TRANSFORMATIONS; SPIN; THIN FILMS; TRANSFORMATIONS; TUNNELING; VALVES; X-RAY DIFFRACTION

Citation Formats

Ji, C. -X., Ladwig, Peter F., Ott, Ronald D, Yang, Y., Yang, Joshua J., Chang, Y. Austin, Linville, Eric S., Gao, Jenny, and Pant, Bharat B. Investigation of phase transformation behavior in sputter deposited PtMn thin films. United States: N. p., 2006. Web. doi:10.1007/s11837-006-0182-x.
Ji, C. -X., Ladwig, Peter F., Ott, Ronald D, Yang, Y., Yang, Joshua J., Chang, Y. Austin, Linville, Eric S., Gao, Jenny, & Pant, Bharat B. Investigation of phase transformation behavior in sputter deposited PtMn thin films. United States. doi:10.1007/s11837-006-0182-x.
Ji, C. -X., Ladwig, Peter F., Ott, Ronald D, Yang, Y., Yang, Joshua J., Chang, Y. Austin, Linville, Eric S., Gao, Jenny, and Pant, Bharat B. Sun . "Investigation of phase transformation behavior in sputter deposited PtMn thin films". United States. doi:10.1007/s11837-006-0182-x.
@article{osti_978162,
title = {Investigation of phase transformation behavior in sputter deposited PtMn thin films},
author = {Ji, C. -X. and Ladwig, Peter F. and Ott, Ronald D and Yang, Y. and Yang, Joshua J. and Chang, Y. Austin and Linville, Eric S. and Gao, Jenny and Pant, Bharat B.},
abstractNote = {Sputter-deposited, equiatomic PtMn thin films have application in giant magnetoresistive spin valves, tunneling magnetoresistive spin valves, and magnetic random access memory. However, the as-deposited films are found to be a disordered A1 phase in a paramagnetic state rather than an antiferromagnetic phase with L1{sub 0} structure, which is needed for device operation. Therefore, a postannealing step is required to induce the phase transformation from the as-deposited A1 face-centered-cubic phase to the antiferromagnetic L1{sub 0} phase. The A1 to L1{sub 0} metastable transformation was studied by x-ray diffraction and differential-scanning calorimetry. An exothermic transformation enthalpy of -12.1 kJ/mol of atoms was determined. The transformation kinetics were simulated using the Johnson-Mehl-Avrami analysis.},
doi = {10.1007/s11837-006-0182-x},
journal = {Journal of the Minerals Metals & Materials Society (JOM)},
number = 6,
volume = 58,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
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  • No abstract prepared.
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