SWIFT HEAVY ION INDUCED NANOHILL FORMATION ON THE SURFACE OF GaP

2011 ◽  
Vol 10 (01n02) ◽  
pp. 105-109 ◽  
Author(s):  
R. L. DUBEY ◽  
S. K. DUBEY ◽  
A. D. YADAV ◽  
D. KANJILAL
Keyword(s):  
Atomic Force Microscopy ◽  
Crystallite Size ◽  
Gallium Phosphide ◽  
Phonon Mode ◽  
Heavy Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Swift Heavy Ion

Gallium phosphide ( GaP ) samples were irradiated with swift (100 MeV)56 Fe 9+ ions for various ion fluences varying from 1 × 1011 to 1 × 1014 cm -2. Atomic force microscopy, Raman scattering, and X-ray diffraction techniques have been used to investigate the irradiation effect. Atomic force microscopy studies showed the presence of nanosized hills separated with valleys at the surface of irradiated gallium phosphide. The average diameters of hills were found to be 19.76, 19.81, 20.70, and 22.64 nm for ion fluences 5 × 1012, 1 × 1013, 5 × 1013, and 1 × 1014 cm -2, respectively. Root mean square surface roughness analysis has been used to characterize the nature of the surface under swift heavy ion irradiation. The features observed in the Raman spectra at 402.18 cm-1 and 365.05 cm-1 were assigned to the characteristic first-order longitudinal optical (LO) phonon mode and transverse optical (TO) phonon mode of gallium phosphide, respectively. We have also observed the second-order overtones and combinations of optical modes giving rise to three characteristic peaks in the region between 700 and 800 cm-1. X-ray diffraction technique has been used to determine the crystallite size. The crystallite size was found to decrease with increase in ion fluence.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Characterization of X-ray irradiated graphene oxide coatings using X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy

2013 ◽  
Vol 28 (2) ◽  
pp. 68-71 ◽  
Author(s):  
Thomas N. Blanton ◽  
Debasis Majumdar
Keyword(s):  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
High Energy ◽  
X Ray Diffraction ◽  
Carbon Phase ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After

In an effort to study an alternative approach to make graphene from graphene oxide (GO), exposure of GO to high-energy X-ray radiation has been performed. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) have been used to characterize GO before and after irradiation. Results indicate that GO exposed to high-energy radiation is converted to an amorphous carbon phase that is conductive.

Effect of ultra-thin Cu underlayer on the magnetic properties of Ni80Fe50 / Fe50Mn50 films

1999 ◽  
Vol 562 ◽  
Author(s):  
C. Liu ◽  
L. Shen ◽  
H. Jiang ◽  
D. Yang ◽  
G. Wu ◽  
...  
Keyword(s):  
Thin Film ◽  
Atomic Force Microscopy ◽  
Exchange Bias ◽  
Film Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Maximum Value ◽  
Film Roughness

ABSTRACTThe Ni80Fe20/Fe50Mn50,thin film system exhibits exchange bias behavior. Here a systematic study of the effect of atomic-scale thin film roughness on coercivity and exchange bias is presented. Cu (t) / Ta (100 Å) / Ni80Fe20 (100 Å) / Fe50Mno50 (200 Å) / Ta (200 Å) with variable thickness, t, of the Cu underlayer were DC sputtered on Si (100) substrates. The Cu underlayer defines the initial roughness that is transferred to the film material since the film grows conformal to the initial morphology. Atomic Force Microscopy and X-ray diffraction were used to study the morphology and texture of the films. Morphological characterization is then correlated with magnetometer measurements. Atomic Force Microscopy shows that the root mean square value of the film roughness exhibits a maximum of 2.5 Å at t = 2.4 Å. X-ray diffraction spectra show the films are polycrystalline with fcc (111) texture and the Fe50Mn50 (111) peak intensity decreases monotonically with increasing Cu thickness, t. Without a Cu underlayer, the values of the coercivity and loop shift are, Hc = 12 Oe and Hp = 56 Oe, respectively. Both the coercivity and loop shift change with Cu underlayer thickness. The coercivity reaches a maximum value of Hc= 36 Oe at t = 4 Å. The loop shift exhibits an initial increase with t, reaches a maximum value of HP = 107 Oe at t = 2.4 Å, followed by a decrease with greater Cu thickness. These results show that a tiny increase in the film roughness has a huge effect on the exchange bias magnitude.

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