Laser-induced modification of amorphous GST225 phase change materials

2019 ◽  
Vol 107 (3) ◽  
pp. 307
Author(s):  
Sergey A. Kozyukhin ◽  
Petr I. Lazarenko ◽  
Yuri V. Vorobyov ◽  
Mikhail S. Savelyev ◽  
Alexander A. Polokhin ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Crystallization Behavior ◽  
Phase Change Materials ◽  
Laser Pulses ◽  
Nanosecond Laser ◽  
Force Microscopy ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Nanosecond Laser Pulses

In this paper, we have studied the crystallization behavior of amorphous GST225 thin films upon irradiation with nanosecond laser pulses. Crystalline and melt-quenched amorphous regions were produced by exposure to laser single or multipulses, and were characterized by the optical microscopy and by the micro-Raman spectroscopy. Transition region between the amorphous and crystalline parts of the laser-modified area was investigated by atomic force microscopy. Using irradiation by single laser pulses with varying fluence, it was verified that crystallization was possible if the fluence is more than 90.4 mJ/cm2.

Fabrication of Micro-Grating Structure on Glazed Stainless-Steel by Two-Beam Holographic Method Using Nanosecond Laser Pulses

2007 ◽  
Vol 364-366 ◽  
pp. 1133-1137
Author(s):  
Heng Zhang ◽  
Yun Zhou ◽  
Lin Sen Chen
Keyword(s):  
Stainless Steel ◽  
Duty Cycle ◽  
Laser Pulses ◽  
New Method ◽  
Nanosecond Laser ◽  
Beam Diameter ◽  
Force Microscopy ◽  
Atomic Force ◽  
Experimental Parameters ◽  
Nanosecond Laser Pulses

A new method of etching micro-grating structures (MGSs) on the surface of glazed stainless-steel directly is reported, which makes good use of the interference of nanosecond laser pulses. Through changing the experimental parameters such as working current of the laser and source beam diameter, the influences of these parameters on the depth of grooves and duty cycle of MGSs are analyzed. The results measured with conventional optical microscopy and atomic force microscopy (AFM) show that the depth of grooves of MGSs varies from 0 nm to 350 nm, the duty cycle of MGSs changes between 0.4 and 0.9, This method can be used to make a stencil-plate for nano-imprinting. It extends the application of nanosecond laser in laser-induced microstructures, and provides a new method for micromachining micro-optical component.

Optical Dielectric Apertureless Probe for Surface Laser Modification with λ/15 Lateral Resolution

2014 ◽  
Vol 213 ◽  
pp. 210-215
Author(s):  
Aleksandr A. Kuchmizhak ◽  
Oleg B. Vitrik ◽  
Yuri N. Kulchin ◽  
A.G. Savchuk
Keyword(s):  
Laser Pulses ◽  
Minimum Size ◽  
Nanosecond Laser ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Laser ◽  
Optical Dielectric ◽  
Tapered Optical Fiber ◽  
Nanosecond Laser Pulses ◽  
First Time

A simple apertureless dielectric microprobe in the form of a section of the tapered optical fiber was proposed for surface laser nanomodification. This probe enables surface λ/2-localization of laser beam, as shown both numerically and experimentally. The controllable formation of single through nanoholes with the minimum size down to 35 nm (~λ/15) in the 50-nm Au/Pd film was shown using this probe and a 532-nm pump nanosecond laser. We also report for the first time on the formation of micro-and nanobumps, jet-like microstructures and microholes on optically thick gold films by single nanosecond laser pulses focused through the fiber dielectric apertureless probe. The resulting structures were imaged via scanning electron and atomic force microscopy. It was shown that both the shape and sizes of the obtained microstructures are determined by the pulse energy and film thickness.

Formation of the YBa2Cu2NbOy phase in thin films

2009 ◽  
Vol 24 (1) ◽  
pp. 212-216
Author(s):  
Srinivas Sathiraju ◽  
Paul N. Barnes ◽  
Robert A. Wheeler
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
New Phase

We report the systematic substitution of Nb at the Cu1 site of YBa2Cu3Oy in thin films to form a new phase of YBa2Cu2NbO8. These films were deposited on SrTiO3(100) crystals using pulsed laser deposition and deposited at an optimal temperature of 850 °C. Films were characterized using x-ray diffraction (XRD), atomic force microscopy, x-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, and transmission electron microscopy. XRD of these films indicate c-axis oriented YBa2Cu2NbOy formation. XPS and micro-Raman spectroscopy analysis suggests Cu exists in the +2 state.

Modeling of Temperature Cycles Induced by Pico- and Nanosecond Laser Pulses in Zinc Oxide and Molybdenum Thin Films

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
D. Scorticati ◽  
G. R. B. E. Römer ◽  
A. J. Huis in't Veld ◽  
D. F. de Lange
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Zinc Oxide ◽  
Pulse Repetition Frequency ◽  
Laser Pulses ◽  
Temperature Fields ◽  
Nanosecond Laser ◽  
Pulsed Lasers ◽  
Temperature Cycles ◽  
Nanosecond Laser Pulses

The aim of this paper is to study the benefits of applying ultrashort pulsed lasers over nanosecond pulsed lasers for selective (i.e., superficial) heat treatment of materials in general and for selective heat treatment of thin films in particular. To this end, a background of the physics that govern the absorption of light and subsequent diffusion of heat in semiconductor and metallic materials is provided, when exposed to picosecond or nanosecond laser pulses, with a fluence below the ablation threshold. A numerical model was implemented using a commercial finite-element modeling package, to simulate the temperature fields in thin films induced by laser pulses. The results of the simulations provide insight in the temperature cycles and corresponding timescales, as function of the processing parameters, such as fluence, pulse duration, pulse repetition frequency, and laser wavelength. Numerical simulations were run for thin films of molybdenum (Mo) and zinc oxide (ZnO) on a glass substrate, which are materials commonly adopted as (back and front) electrodes in thin film solar cells.

Optical limiting properties of BODIPY dyes substituted with styryl or vinylene groups on the nanosecond timescale

2019 ◽  
Vol 23 (07n08) ◽  
pp. 701-717 ◽  
Author(s):  
Nobuhle Ndebele ◽  
Zweli Hlatshwayo ◽  
Bokolombe P. Ngoy ◽  
Gugu Kubheka ◽  
John Mack ◽  
...  
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Laser Pulses ◽  
Optical Limiting ◽  
Nanosecond Laser ◽  
Third Order ◽  
The Third ◽  
Nanosecond Laser Pulses ◽  
532 Nm ◽  
Order Susceptibility

The results of recent studies on the optical limiting properties of BODIPY dyes at 532 and 1064 nm are described and compared. The optical limiting properties of novel 1,7-dimethyl-3,5-di-4-dihydroxyborylstyryl- and 3,5,7-tristyryl-1-methyl-BODIPY dyes were studied in CH2Cl2 and C6H6 and polystyrene thin films using the open aperture Z-scan technique at 532 nm with nanosecond laser pulses to provide an example of how the effective nonlinear absorption coefficient, the third order susceptibility, hyperpolarizability and limiting thresholds can be calculated.

Locally formation of Ag nanoparticles in chalcogenide phase change thin films induced by nanosecond laser pulses

2012 ◽  
Vol 135 (2-3) ◽  
pp. 467-473 ◽  
Author(s):  
Huan Huang ◽  
Lei Zhang ◽  
Yang Wang ◽  
Xiaodong Han ◽  
Yiqun Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Change ◽  
Ag Nanoparticles ◽  
Laser Pulses ◽  
Nanosecond Laser ◽  
Nanosecond Laser Pulses
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