Third Day Poster Session, 17 June 2010 - NanoTR-VI

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Poster Session, Thursday, June 17
Theme F686 - N1123
Nano Isotopic Optical Centres in HPHT and CVD Synthetic Diamond Types
1
UHamida M. B. DarwishU
P*
1
PPhysics Department, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
Abstract - Eelectron irradiated synthetic diamond exhibited a number of new local vibrational moods (LVM) which have three fold splitting
of their highest energy. The magnitude of the energies of each of these modes varies as the square root of the isotopic carbon of atomic masses.
One of these centers is the zero Phonon line (ZPL) 389 nm (3.188eV) The second is the ZPL 420 nm (2.951eV).
Synthetic and natural diamonds generated greatly renewed
interest to develop the optoelectronic applications and devices
that are unaffected by high temperature or by other adverse
environmental conditions such as heat spreaders, optical
windows, electrical conductors, and nano-optoelectronic
devices that can be used in high industry purposes for such as
medical research and space searches and satellites. Also it can
be demanded as cutting tool or polishing in the iron and steel,
car Factories and plants [1, 2].
The physical properties of diamond exhibit that diamond
fully transparent from infrared through the near ultraviolet [3].
It has highest velocity of sound. It is a fully resistance to heat,
radiation and chemical reaction and stable at room
temperature and pressure. It a promising material it has a
unique properties such as the highest semiconductor properties
which exceeds that of SiC [3]. So there is more reason for
studying diamond. But diamond is very expensive and rare in
nature. And the study of the different spectra manifested by
natural and synthetic may tell us more about how the former
were created and how to grow the latter more efficiency. Now
synthetic diamonds are available but nitrogen and boron are
the only impurities which can be introduced into them with
some degree of control
Synthetic diamond samples grown by two methods
chemical vapour deposition (CVD) [4] and high pressure high
temperature (HPHT) [5, 6] have been investigated (after
irradiation by TEM) by Photoluminescence (PL) technique.
This studying was preformed after annealing at elevated
0
0
temperatures between 773P PK and 1073 P PK. The investigation
predicts many numbers of new local vibrational modes (LVM)
with optical isotopic centres, which split into three- folds as
the square root of carbon masses as shown in Figure 1 and 2.
Figure 1. LVM of ZPL 389 nm for PL of P
PC P
PC doping HPHT
0
diamond sample annealed at 1073 P Pk. (Using UV laser)
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Figure 1 reveals PL spectrum of irradiated P
PC P
PC doping
0
HPHT diamond sample after annealing at 1073 P Pk by using
UV laser. The zero phonon line (ZPL) at the centre of 390 nm
with its local vibrational mood (LVM) is splitting into three
folds as the squire root of the isotopic carbon atomic masses at
the centres of 412.28 nm, 412.85 nm and 413.28 nm.
.
Figure 2. LVM of the ZPL 420 nm for PL P
PC P
PC –doping HPHT
diamond sample by using UV. Laser (325nm)
Figure 2 displays the local vibrational mood (LVM) of the
same sample associated; with the zero phonon line at the
centre 420 nm. Also this centre is divided into three folds as
the isotopic carbon masses at the centres of 449.25 nm, 449.85
nm and 450.5 nm.
The well known LVM of the centre 390 nm have been found
in all types of CVD and HPHT diamond samples (Carbon,
Boron and Nitrogen-doping samples) that studied at this work.
This LVM is splitting for the first time into three folds as the
squire roots of the isotopes of the atomic carbon masses. Also
the investigation of HPHT electron irradiated carbon-doping
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50-50 P
PC/ P
PC diamond samples predicts the centres 420 nm
besides the ZPL 390 nm and they are splitting as the squire
root of isotopic carbon masses, which have three–fold is
splitting of their highest energy local vibrational modes. (More
details about this work will be written later) .
This study was supported by KSA Ministry of Higher
Education, Bristol University-UK and diamond samples
supplier.
*Corresponding author: hdarwish@kau.edu.sa
[1] F. Bundy, H. T. Hall, M. M. Strong, R. H. Wentorf: Nature 176,
50-51, (1955)
[2] R. M. Chrenko, Phys. Rev. B7, Pp. 4560-4567, (1973)
[3] J. Walker: Optical Absorption and Luminescence in Diamond,
Rep. Prog,. Phys., 42, Pp 1605-1659, (1979)
[4] K. Snail: Growth, Processing and Properties of CVD Diamond for
Optical Application, Opt. Mater., Vol. 1, Pp. 235-258 (1992)
[5] S. Yamaoka et al., Diamond & Related Materials, V. 9, Issue 8,
1480-1486, (2000)
[6] J. E. Field: The Properties of Natural and Synthetic Diamond,
Academic press. London (1992)
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6th Nanoscience and Nanotechnology Conference, zmir, 2010 643