1. Magnetism Laboratory, Department of Physics, COMSATS Institute of Information Technology, 45550 Islamabad, Pakistan
2. Center for Micro and Nano Devices (CMND), Department of Physics, COMSATS Institute of Information Technology, 45550 Islamabad, Pakistan
3. Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
4. Institute for Metallic Materials, IFW Dresden, 01069 Dresden, Germany
5. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA