scholarly journals Defining the true hardness of materials harder than single crystal diamond

Author(s):  
Guodong (David) Zhan ◽  
Jin Liu ◽  
Pei Wang ◽  
Liping Wang ◽  
Xiaozhi Yan ◽  
...  

Abstract With the development of new synthesis methods and chemistries, a number of new superhard materials have been reported to be harder than diamond. While such materials are highly desirable due to their wide-ranging applications, there are some inherent uncertainties in the methods utilized to determine and define the hardness of such materials. In this paper, we employed the Vickers Hardness Tester to measure the hardness of nine ceramic and superhard materials within a well-defined criteria and methodology, for the reliable assessment of the hardness of these new superhard materials. These findings and the developed testing method have broad implications in the characterizing of new and emerging superhard materials, leading to new discoveries.

2021 ◽  
Vol 1 (1) ◽  
pp. 143-149
Author(s):  
Wei Cao ◽  
Deng Gao ◽  
Hongyang Zhao ◽  
Zhibin Ma

1995 ◽  
Vol 416 ◽  
Author(s):  
L. C. Chen ◽  
C. C. Juan ◽  
J. Y. Wu ◽  
K. H. Chen ◽  
J. W. Teng

ABSTRACTNear-single-crystal diamond films have been obtained in a number of laboratories recently. The optimization of nucleation density by using a bias-enhanced nucleation (BEN) method is believed to be a critical step. However, the condition of optimized nucleation has never been clearly delineated. In the present report, a novel quantitative technique was established to monitor the nucleation of diamond in-situ. Specifically, the induced current was measured as a function of nucleation time during BEN. The timedependence of induced current was studied under various methane concentrations as well as substrate temperatures. The optimized nucleation condition can be unambiguously determined from the current-time plot. Besides the in-situ current probe, ex-situ x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were also used to investigate the chemical and morphological evolution. Characteristic XPS and AFM features of optimized nucleation is discussed.


2009 ◽  
Vol 1203 ◽  
Author(s):  
Jen Bohon ◽  
John Smedley ◽  
Erik M. Muller ◽  
Jeffrey W. Keister

AbstractHigh quality single crystal and polycrystalline CVD diamond detectors with platinum contacts have been tested at the white beam X28C beamline at the National Synchrotron Light Source under high-flux conditions. The voltage dependence of these devices has been measured under DC and pulsed-bias conditions, establishing the presence or absence of photoconductive gain in each device. Linear response has been achieved over eleven orders of magnitude when combined with previous low flux studies. Temporal measurements with single crystal diamond detectors have resolved the ns scale pulse structure of the NSLS.


1993 ◽  
Vol 70 (24) ◽  
pp. 3764-3767 ◽  
Author(s):  
Lanhua Wei ◽  
P. K. Kuo ◽  
R. L. Thomas ◽  
T. R. Anthony ◽  
W. F. Banholzer

1994 ◽  
Vol 354 ◽  
Author(s):  
Shuji Kiyohara ◽  
Iwao Miyamoto

AbstractIn order to apply ion beam etching with hydrogen ions to the ultra-precision processing of diamond tools, hydrogen ion beam etching characteristics of single crystal diamond chips with (100) face were investigated. The etching rate of diamond for 500 eV and 1000 eV hydrogen ions increases with the increase of the ion incidence angle, and eventually reaches a maximum at the ion incidence angle of approximately 50°, then may decrease with the increase of the ion incidence angle. The dependence of the etching rate on the ion incidence angle of hydrogen ions is fairly similar to that obtained with argon ions. Furthermore, the surface roughness of diamond chips before and after hydrogen ion beam etching was evaluated using an atomic force microscope. Consequently, the surface roughness after hydrogen ion beam etching decreases with the increase of the ion incidence angle within range of the ion incidence angle of 60°.


2021 ◽  
pp. 150431
Author(s):  
Longxing Liao ◽  
Zhenyu Zhang ◽  
Fanning Meng ◽  
Dongdong Liu ◽  
Bin Wu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document