We report the discovery of a new phase of carbon (referred to as Q-carbon) and address fundamental issues related to direct conversion of carbon into diamond at ambient temperatures and pressures in air without any need for catalyst and presence of hydrogen. The Q-carbon is formed as result of quenching from super undercooled state by using high-power nanosecond laser pulses. We discuss the equilibrium phase diagram (P vs. T) of carbon and show that by rapid quenching kinetics can shift thermodynamic graphite/diamond/liquid carbon triple point from 5000 K/12 GPa to super undercooled carbon at atmospheric pressure in air. It is shown that nanosecond laser heating of diamond-like amorphous carbon on sapphire, glass, and polymer substrates can be confined to melt carbon in a super undercooled state. By quenching the carbon from the super undercooled state, we have created a new state of carbon (Q-carbon) from which nanodiamond, microdiamond, microneedles, and single-crystal thin films are formed depending upon the nucleation and growth times allowed for diamond formation. The Q-carbon quenched from liquid is a new state of solid carbon with a higher mass density than amorphous carbon and a mixture of mostly fourfold sp3 (75%–85%) with the rest being threefold sp2 bonded carbon (with distinct entropy). It is expected to have new and improved mechanical hardness, electrical conductivity, chemical, and physical properties, including room-temperature ferromagnetism (RTFM) and enhanced field emission. Here we present interesting results on RTFM, enhanced electrical conductivity and surface potential of Q-carbon to emphasize its unique properties. The Q-carbon exhibits robust bulk ferromagnetism with estimated Curie temperature of about 500 K and saturation magnetization value of 20 emu g−1. From the Q-carbon, diamond phase is nucleated and a variety of micro- and nanostructures and large-area single-crystal diamond sheets are grown by allowing growth times as needed. Subsequent laser pulses can be used to grow nanodiamond into microdiamond and nucleate other nanostructures of diamond on the top of existing microdiamond and create novel nanostructured materials. The microstructural details provide insights into the mechanism of formation of nanodiamond, microdiamond, nanoneedles, microneedles, and single-crystal thin films. This process allows carbon-to-diamond conversion and formation of useful nanostructures and microstructures at ambient temperatures in air at atmospheric pressure on practical and heat-sensitive substrates in a controlled way without need for any catalysts and hydrogen to stabilize sp3 bonding for diamond formation.
Skip Nav Destination
Article navigation
7 December 2015
Research Article|
December 02 2015
Novel phase of carbon, ferromagnetism, and conversion into diamond
Jagdish Narayan;
Jagdish Narayan
a)
Department of Materials Science and Engineering,
Centennial Campus, North Carolina State University
, Raleigh, North Carolina 27695-7907, USA
Search for other works by this author on:
Anagh Bhaumik
Anagh Bhaumik
Department of Materials Science and Engineering,
Centennial Campus, North Carolina State University
, Raleigh, North Carolina 27695-7907, USA
Search for other works by this author on:
a)
Author to whom correspondence should be addressed. Electronic mail: [email protected]
J. Appl. Phys. 118, 215303 (2015)
Article history
Received:
September 16 2015
Accepted:
November 10 2015
Citation
Jagdish Narayan, Anagh Bhaumik; Novel phase of carbon, ferromagnetism, and conversion into diamond. J. Appl. Phys. 7 December 2015; 118 (21): 215303. https://doi.org/10.1063/1.4936595
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
A step-by-step guide to perform x-ray photoelectron spectroscopy
Grzegorz Greczynski, Lars Hultman
Piezoelectric thin films and their applications in MEMS: A review
Jinpeng Liu, Hua Tan, et al.
Tutorial: Simulating modern magnetic material systems in mumax3
Jonas J. Joos, Pedram Bassirian, et al.
Related Content
Highly intensive emission of the NV− centers in synthetic HPHT microdiamonds at low nitrogen doping
APL Mater. (August 2018)
Nano-to-micro diamond formation by nanosecond pulsed laser annealing
J. Appl. Phys. (September 2019)
Direct conversion of h-BN into c-BN and formation of epitaxial c-BN/diamond heterostructures
J. Appl. Phys. (May 2016)
Optically detected magnetic resonance of nitrogen vacancies in a diamond anvil cell using designer diamond anvils
Appl. Phys. Lett. (November 2017)
Novel tungsten oxide microneedles with nanosized tips
Appl. Phys. Lett. (May 2006)