scholarly journals Picosecond x-ray strain rosette reveals direct laser excitation of coherent transverse acoustic phonons

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Sooheyong Lee ◽  
G. Jackson Williams ◽  
Maria I. Campana ◽  
Donald A. Walko ◽  
Eric C. Landahl
Keyword(s):  
Laser Excitation ◽  
Acoustic Phonons ◽  
X Ray ◽  
Transverse Acoustic ◽  
Direct Laser ◽  
Strain Rosette

Scanning electron microscopy (SEM) and X-ray dispersive spectrometry evaluation of direct laser metal sintering surface and human bone interface: a case series

2010 ◽  
Vol 26 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Carlo Mangano ◽  
Adriano Piattelli ◽  
Mario Raspanti ◽  
Francesco Mangano ◽  
Alessandra Cassoni ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Case Series ◽  
Human Bone ◽  
X Ray ◽  
Bone Interface ◽  
Direct Laser ◽  
Metal Sintering ◽  
Scanning Electron

scholarly journals Picosecond X-ray diffraction studies of laser-excited acoustic phonons in InSb

2002 ◽  
Vol 75 (4) ◽  
pp. 467-478 ◽  
Author(s):  
J. Larsson ◽  
A. Allen ◽  
P.H. Bucksbaum ◽  
R.W. Falcone ◽  
A. Lindenberg ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Acoustic Phonons ◽  
X Ray

scholarly journals Low-Power Laser Graphitization of High Pressure—High Temperature Nanodiamond Films

2020 ◽  
Vol 10 (9) ◽  
pp. 3329
Author(s):  
Konstantin G. Mikheev ◽  
Tatyana N. Mogileva ◽  
Arseniy E. Fateev ◽  
Nicholas A. Nunn ◽  
Olga A. Shenderova ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Laser Excitation ◽  
X Ray Diffraction ◽  
Power Laser ◽  
Green Luminescence ◽  
X Ray ◽  
Atomic Force ◽  
High Pressure High Temperature ◽  
Before And After

Laser-induced graphitization of 100 nm monocrystals of diamond particles synthesized by high-pressure high-temperature (HP-HT) methods is not typically observed. The current study demonstrates the graphitization of 150 nm HP-HT nanodiamond particles in ca. 20-μm-thick thin films formed on a glass substrate when the intensity of a focused 633 nm He-Ne laser exceeds a threshold of ~ 33 kW/cm2. Graphitization is accompanied by green luminescence. The structure and morphology of the samples were investigated before and after laser excitation while using X-ray diffraction (XRD), Raman spectroscopy, atomic force (AFM), and scanning electron microscopy (SEM). These observations are explained by photoionization of [Ni-N]- and [N]-centers, leading to the excitation of electrons to the conduction band of the HP-HT nanodiamond films and an increase of the local temperature of the sample, causing the transformation of sp3 HP-HT nanodiamonds to sp2-carbon.

Probing disorder in high-pressure cubic tin (IV) oxide: a combined X-ray diffraction and absorption study

2019 ◽  
Vol 26 (4) ◽  
pp. 1245-1252 ◽  
Author(s):  
Daniel Sneed ◽  
John S. C. Kearney ◽  
Dean Smith ◽  
Jesse S. Smith ◽  
Changyong Park ◽  
...  
Keyword(s):  
High Pressure ◽  
Laser Heating ◽  
High Pressures ◽  
Transparent Conducting Oxide ◽  
Large Degree ◽  
X Ray Diffraction ◽  
Quality Of Data ◽  
X Ray ◽  
Direct Laser ◽  
Gap Opening

The transparent conducting oxide, SnO2, is a promising optoelectronic material with predicted tailorable properties via pressure-mediated band gap opening. While such electronic properties are typically modeled assuming perfect crystallinity, disordering of the O sublattice under pressure is qualitatively known. Here a quantitative approach is thus employed, combining extended X-ray absorption fine-structure (EXAFS) spectroscopy with X-ray diffraction, to probe the extent of Sn—O bond anharmonicities in the high-pressure cubic (Pa\bar{3}) SnO2 – formed as a single phase and annealed by CO2 laser heating to 2648 ± 41 K at 44.5 GPa. This combinational study reveals and quantifies a large degree of disordering in the O sublattice, while the Sn lattice remains ordered. Moreover, this study describes implementation of direct laser heating of non-metallic samples by CO2 laser alongside EXAFS, and the high quality of data which may be achieved at high pressures in a diamond anvil cell when appropriate thermal annealing is applied.

scholarly journals The theory of direct laser excitation of nuclear transitions

2020 ◽  
Vol 56 (7) ◽  
Author(s):  
Lars von der Wense ◽  
Pavlo V. Bilous ◽  
Benedict Seiferle ◽  
Simon Stellmer ◽  
Johannes Weitenberg ◽  
...  
Keyword(s):  
Laser Excitation ◽  
Direct Laser ◽  
Nuclear Transitions

Yellow-Orange Upconversion Luminescence in NaYF4:Er3+, Yb3+ Phosphor Synthesized by Microwave Combustion Method

2011 ◽  
Vol 295-297 ◽  
pp. 551-554 ◽  
Author(s):  
Jia Yue Sun ◽  
Chun Cao ◽  
Hai Yan Du
Keyword(s):  
Laser Excitation ◽  
Upconversion Luminescence ◽  
Green Emission ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Photon ◽  
Yellow Orange ◽  
Photon Process ◽  
Microwave Combustion Method

Erbium and ytterbium co-doped sodium yttrium fluoride (NaYF4:Er3+,Yb3+) was synthesized by combusting in home microwave oven directly. The structure and morphology of the sample was characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM), and its upconversion luminescence properties were investigated in detail. Under 980nm semiconductor laser excitation, the color of upconversion luminescence of NaYF4:Er3+,Yb3+ was green and red, and its upconversion spectrum exhibited distinct emission peaks at 522, 543 and 652 nm, the emission appears yellow-orange to the naked eye. The law of luminescence intensity versus pump power proved that the intense green emission at 522 and 543 nm were from Er3+(2H11/2→4I15/2and4S3/2→4I15/2), and the weaker red emission at 652 nm was from Er3+(4F9/2→4I15/2), which belong to the two photon process.

Effect of laser excitation on F-band absorption and thermoluminescence of X-ray irradiated KBr single crystals

1986 ◽  
Vol 21 (12) ◽  
pp. 4315-4317 ◽  
Author(s):  
G. Prasad ◽  
B. K. Roul ◽  
R. N. P. Chaudhary ◽  
K. V. Rao
Keyword(s):  
Single Crystals ◽  
Laser Excitation ◽  
X Ray ◽  
Band Absorption
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