| Characterization of As-Deposited Crystalline NiTi Thin Films | ||
| Mr. David Bronfenbrenner1, Dr. Velimir Radmilovic2, Dr. Scott A. McHugo3 and Prof. Ronald Gronsky1, 1Materials Science and Engineering, University of California, 210 Hearst Memorial Mining Building, Berkeley, CA 94720-1760, 2National Center for Electron Microscopy, Lawrence Berkeley National Labs, 1 Cyclotron Road, Mail Stop 72-150, Berkeley, CA 94720, 3Nitinol Devices & Components, 47533 Westinghouse Drive, Fremont, CA 94539
Sputter deposited NiTi thin film has shown great promise in biomaterial applications for its biocompatibility, superelasticity, and shape memory properties. As the number of applications for this material increases, it is important to verify the consistency of the sputter deposited films at the microstructural level. As-deposited crystalline thin film NiTi was analyzed to determine the phase distribution, microstructure, and transformation properties at given sputter deposition parameters. Transmission electron microscopy and x-ray diffraction were used to assess the phase distribution and microstructure of the thin film product. In addition, the transformation properties were studied using differential scanning calorimetry and atomic force microscopy. The films were shown to have a phase distribution of approximately 90% martensite and 10% R-phase, a grain size of 100-500 nm, and an Af of 80oC. | ||