Deposition of molybdenum carbide thin films by dense plasma focus device

Abstract

This work was motivated by the promising physiochemical properties and catalytic activity of molybdenum carbide. Thin films of molybdenum carbide were deposited on the mono-crystalline cubic Si (400) substrate by utilizing a 3.6 kJ dense plasma focus device (Mather-type) with multiple shots. The structure of the films was examined by X-ray diffraction (XRD). XRD results indicated the absence of crystalline film for 5 focus shots, while for increased numbers of focus shots, the emergence of Mo-C peaks in the orientations (120), (014) and (232) confirmed the formation of orthorhombic β-Mo₂C polycrystalline films. Moreover, a small variation in the crystallite size was observed by increasing the number of focus shots. The presence of molybdenum and carbon was confirmed by energy-dispersive X-ray (EDX) analysis. Surface morphology was studied under scanning electron microscope (SEM). SEM micrographs revealed non-uniform films with some surface defects such as cracks and craters of micron size, and rough surface. Revealed by the ellipsometry technique, the film thickness increased by increasing the number of focus shots. The electric conductivity, measured by the four-point probe technique, was the highest for 10 focus shots. However, the films have some structural defects, low conductivity and impurities like silicon and silicon carbide, but it was the first ever successful attempt to deposit molybdenum-carbide (Mo₂C) thin films using the dense plasma focus device.

Keywords:

• DPF
• focus shots
• molybdenum carbide
• XRD
• sputtering

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Kishawar Khan

Mr. Kishawar Khan is a Lecturer in Physics at IPS & College Kabal, Swat, Pakistan. He obtained his undergraduate degree in physics (2011) from Federal Urdu University of Arts, Science and Technology Karachi, Pakistan. He did his masters (MPhil.) in Applied Physics (2016) from Center for Advance Studies in Physics (CASP) GC University Lahore, Pakistan under the supervision of Professor Dr. Riaz Ahmad.

Riaz Ahmad

Dr. Riaz Ahmad is Professor of Physics at GC University Lahore, Pakistan. In addition, he is also Director of Institute of Physics, Chairman of Department of Physics, and Dean of Faculty of Mathematical and Physical Sciences and Faculty of Engineering, GC University Lahore, Pakistan. He has been teaching physics in GC University since 1997. He received his Ph.D. in Physics from Imperial College of Science, Technology and Medicine, London, United Kingdom (1992). He established Plasma Technology lab at G C University Lahore in which three experimental facilities, namely a plasma focus (3kJ), Magnetron Sputtering Facility, Cold Plasma Facility, and mini focus (10kJ) machine. He has received several awards and honors such as Academic Roll of Honor (1986), Scholarship for PhD from Ministry of Science and Tech. (1988), HEC Best teacher Award (2010), and Gold Medal in Physics by Pakistan Academy of Sciences (2018).

Tousif Hussain

Dr. Tousif Hussain is an Associate Professor of Physics at Center for Advance Studies in Physics (CASP), GC University Lahore, Pakistan. He did PhD in Physics (2012) from GC University Lahore, Pakistan under the supervision of Prof. Dr. Riaz Ahmad. He has been approved as PhD supervisor by HEC (2012). He has been teaching physics in GC University since 2007. His research interest areas are Experimental Plasma and Material Science.

Uzma Ikhlaq

Dr. Uzma Ikhlaq serves as an Assistant Professor of Physics at Department of Physics, University of Sahiwal, Sahiwal, Pakistan. She did PhD in Physics (2016) from GC University Lahore, Pakistan under the supervision of Prof. Dr. Riaz Ahmad. She has been teaching physics in University of Sahiwal since 2019. She has remained incharge of X-Ray diffraction Laboratory at Government College University Lahore from 2009 to 2019. Her research interest areas are Cold Plasma, Pulsed Plasma, XRD Sample Analysis.