What began as research into a method to strengthen metals has led to the discovery of a new technique that uses a pulsing laser to create synthetic nanodiamond films and patterns from graphite, with potential applications from biosensors to computer chips.
"The biggest advantage is that you can selectively deposit nanodiamond on rigid surfaces without the high temperatures and pressures normally needed to produce synthetic diamond," said Gary Cheng, an associate professor of industrial engineering at Purdue University. "We do this at room temperature and without a high temperature and pressure chamber, so this process could significantly lower the cost of making diamond. In addition, we realize a direct writing technique that could selectively write nanodiamond in designed patterns."
The ability to selectively "write" lines of diamond on surfaces could be practical for various potential applications including biosensors, quantum computing, fuel cells and next-generation computer chips.
The technique works by using a multilayered film that includes a layer of graphite topped with a glass cover sheet. Exposing this layered structure to an ultrafast-pulsing laser instantly converts the graphite to an ionized plasma and creates a downward pressure. Then the graphite plasma quickly solidifies into diamond. The glass sheet confines the plasma to keep it from escaping, allowing it to form a nanodiamond coating.
"These are super-small diamonds and the coating is super-strong, so it could be used for high-temperature sensors," Cheng said.
Research findings are detailed in a paper that appeared online in the Nature journal Scientific Reports. The paper was authored by former Purdue doctoral students Yuefeng Wang, Yingling Yang, Ji Li and Martin Y. Zhang; postdoctoral research associate Jiayi Shao; doctoral students Qiong Nian and Liang Tang; and Cheng.
The researchers made the discovery while studying how to strengthen metals using a thin layer of graphite and a nanosecond-pulsing laser. A doctoral student noticed that the laser was either causing the graphite to disappear or turn semi-transparent.
"The black coating of graphite was gone, but where did it go?" Cheng said.
Subsequent research proved the graphite had turned into diamond. The Purdue researchers have named the process confined pulse laser deposition (CPLD).
The research team confirmed that the structures are diamond using a variety of techniques including transmission electron microscopy, X-ray diffraction and the measurement of electrical resistance.
A U.S. patent application has been filed on the concept through the Purdue Office of Technology Commercialization. More research is needed to commercialize the technique, Cheng said.
Writer: Emil Venere, 765-494-4709, firstname.lastname@example.org
Source: Gary J. Cheng, 765-494-5436, email@example.com
Direct Laser Writing of Nanodiamond Films from Graphite under Ambient Conditions
Qiong Nian, Yuefeng Wang, Yingling Yang, Ji Li, Martin Y. Zhang, Jiayi Shao, Liang Tang & Gary J. Cheng
Synthesis of diamond, a multi-functional material, has been a challenge due to very high activation energy for transforming graphite to diamond, and therefore, has been hindering it from being potentially exploited for novel applications. In this study, we explore a new approach, namely confined pulse laser deposition (CPLD), in which nanosecond laser ablation of graphite within a confinement layer simultaneously activates plasma and effectively confine it to create a favorable condition for nanodiamond formation from graphite. It is noteworthy that due to the local high dense confined plasma created by transparent confinement layer, nanodiamond has been formed at laser intensity as low as 3.7 GW/cm2, which corresponds to pressure of 4.4 GPa, much lower than the pressure needed to transform graphite to diamond traditionally. By manipulating the laser conditions, semi-transparent carbon films with good conductivity (several kΩ/Sq) were also obtained by this method. This technique provides a new channel, from confined plasma to solid, to deposit materials that normally need high temperature and high pressure. This technique has several important advantages to allow scalable processing, such as high speed, direct writing without catalyst, selective and flexible processing, low cost without expensive pico/femtosecond laser systems, high temperature/vacuum chambers.
Emil Venere | EurekAlert!
Further reports about: > deposit > electrical resistance > electron microscopy > high temperatures > laser intensity > nanodiamond formation > next-generation computer > patent application > potential applications > processing > quantum computing > room temperature > temperature > transmission electron microscopy > vacuum chambers
Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy