1. Nanoscale Sciences Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
2. Materials Characterization and Performance Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
3. Microsystems Integration Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
4. Material, Physical, and Chemical Sciences Center, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States