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 L10 ostructure, which is needed for device operation. Therefore, a post-annealing step is required to induce the phase transformation from the as-deposited A1 face-centered-cubic phase to the antiferromagnetic L10 phase. The A1 to L10 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.
| Original language | English |
|---|---|
| Pages (from-to) | 50-54 |
| Number of pages | 5 |
| Journal | JOM |
| Volume | 58 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2006 |
Funding
The authors appreciate financial sup port from the Division of Materials Sciences, Office of Basic Energy Research of the Department of Energy through grant no. DE-FG02-99ER45777, the Wisconsin Distinguished Professorship, and Seagate Technology. A portion of this research was sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the U.S. Department of Energy under Contract No. DE-AC05-00OR22725.