Nature of magnetism and transport in BxCyNz thin films: The intriguing role of nitrogen defects in the electronic structure
arXiv:1807.11667 · doi:10.1016/j.jmmm.2019.02.014
Abstract
Boron carbonitride (BxCyNz) represents an interesting family of materials containing all light elements and two dimensional graphene like hybrid layers. Although rich literature exists on this peculiar material in chemically processed form, there are relatively fewer reports on device application-worthy thin film form. This form also offers a natural platform for basic studies on important aspects such as magnetism and transport, which have attracted attention in the context of ferromagnetism in doped and defect carbon systems. Thus, in this work we have grown thin films of this compound using Pulsed Laser Deposition (PLD) method, and investigated their magnetic and transport properties in their entirety along with the detailed electronic structure using various spectroscopic techniques like X-ray photoelectron spectroscopy (XPS), Valence Band Spectroscopy (VBS) and X-ray absorption near edge spectroscopy (XANES). In depth analysis of the typical role of dopants and defects, especially the prevalent nitrogen defects, is elucidated using Density Functional Theory (DFT) calculations to understand the experimental observations. A dramatic crossover in the transport mechanism of charge carriers is observed in this system with the change in doping level of specific nitrogen defects. A robust and high saturation magnetization is achieved in BCN films which is higher by almost hundred times as compared to that in similarly grown undoped carbon film. An anomalous transition and increase in coercive field is also observed at low temperature. A careful analysis brings out the intriguing role of specific nitrogen defects in defining the peculiar nature and concentration dependence of the physical properties of this system.
References in corpus (14)
- Spin-half paramagnetism in graphene induced by point defects
- Magnetic Correlations at Graphene Edges
- Room-temperature ferromagnetism in graphite driven by 2D networks of point defects
- Vacancy induced magnetism in graphene and graphene ribbons
- Variable range hopping conduction in semiconductor nanocrystal solids
- Limits on intrinsic magnetism in graphene
- Dual origin of defect magnetism in graphene and its reversible switching by molecular doping
- Efros-Shklovskii variable range hopping in reduced graphene oxide sheets of varying carbon sp2 fraction
- Transport properties of 2D graphene containing structural defects
- Magnetic states and optical properties of single-layer carbon-doped hexagonal boron nitride
- Anomalous insulator metal transition in boron nitride-graphene hybrid atomic layers
- Manipulation of edge magnetism in hexagonal graphene nanoflake
- Magnetic and electronic phase crossovers in graphene nanoflakes
- Turbostratic graphitic microstructures: electronically decoupled multilayer graphene devices with robust high charge carrier mobility