X-Ray Diffraction and Reflectivity Studies of Thin Porous Silicon Layers

1996 ◽  
Vol 452 ◽  
Author(s):  
D. Buttard ◽  
G. Dolino ◽  
D. Bellet ◽  
T. Baumbach

AbstractHigh resolution X-ray diffraction and reflectivity have been used for the structural characterization of thin porous silicon layers of p and p+ doping type. Thin porous silicon layers studied either by diffraction or reflectivity, in the range of 10–1000 nm, exhibit several thickness fringes, corresponding to a lateral homogeneity of the layer thickness. The comparison between the experimental results with simulations enables one to deduce structural information relative to the porosity, thickness, lattice parameter as well as interface thickness. For p+ type samples a double fringe system was observed, showing the existence of a surface film probably at the porous silicon layer top surface.

2012 ◽  
Vol 476-478 ◽  
pp. 1794-1797 ◽  
Author(s):  
Su Xia Guo ◽  
Yi Tan ◽  
Jia Yan Li ◽  
Ya Qiong Li ◽  
Chen Guang Liu

The porous silicon layer was fabricated by electrochemical etching process using an aqueous HF-based electrolyte. The characterizations of porous silicon layer were investigated by Emission-type scanning electron microscope (SEM), Raman spectra and X-ray diffraction (XRD). With the current density increasing, the pore diameter and density become much bigger. This result also was confirmed by Raman spectra and XRD result of samples, which revealed the decreasing of grain size of silicon. The resistivity of crystalline silicon increased when the porous layer was removed after heat treatment at 850°C for 2.5h, which should be attributed to the gettering process of porous silicon.


2000 ◽  
Vol 5 (S1) ◽  
pp. 412-424
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.


1999 ◽  
Vol 595 ◽  
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  

AbstractWe report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.


2011 ◽  
Vol 25 (07) ◽  
pp. 1013-1019 ◽  
Author(s):  
S. AZADEHRANJBAR ◽  
F. KARIMZADEH ◽  
M. H. ENAYATI

Nanocrystalline FeNi and Ni 3 Fe alloys were prepared by mechanical alloying of Fe and Ni elemental powders using a planetary ball mill under protection atmosphere. X-ray diffraction measurements were performed to follow alloy formation process in these alloys. A heat treatment of 1 h at 800°C was carried out to relax the internal stresses of the milled samples. Morphological evolution of powder particles was revealed by scanning electron microscopy. The value of lattice parameter was reached to 0.35762 nm and the hardness was found to be 686 HV at 30 h milled FeNi powder. In the case of Ni 3 Fe the values of 0.3554 nm and 720 HV were obtained for lattice parameter and hardness, respectively.


2015 ◽  
Vol 819 ◽  
pp. 198-203
Author(s):  
Nur Farahin Abdul Hamid ◽  
Rozana Aina Maulat Osman ◽  
Mohd Sobri Idris ◽  
Tze Qing Tan

La-doped barium titanate (BaTiO3) was prepared using conventional solid state synthesis route. All peaks for sample x=0 are approaching the phase pure of BaTiO3 structure with tetragonal crystal structure (P4mm). Sintering of pressed powder are performed at 1300oC, 1400oC and 1450oC for overnight for pure BaTiO3 and 1350oC for 3 days for BaTiO3 doped lanthanum with intermittent grinding. Phase transition was studied by different x composition. The changes in the crystal structure of the composition x=0.1 and 0.2 were detected by using X-ray diffraction (XRD). The phase changes between tetragonal-cubic and cubic-tetragonal depending on the temperature. Rietveld Refinement analysis is carried out to determine the lattice parameter and unit cell for BaTiO3.


2004 ◽  
Vol 51 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Sanjay K. Rai ◽  
Anish Kumar ◽  
Vani Shankar ◽  
T. Jayakumar ◽  
K. Bhanu Sankara Rao ◽  
...  

2017 ◽  
Vol 907 ◽  
pp. 56-60
Author(s):  
Ummuhanı Hilal Özer ◽  
Kerim Emre Öksüz ◽  
Ali Özer

It is well known that sol-gel technique is a simple method to produce nano sized ceramic powders. In this study, cerium oxide doped zirconia samples, with 10 mol%-12mol% and14mol% CeO2, were synthesized by sol-gel technique and characterized. The surface morphology, elemental composition, microstructure, and phase analysis, of the sintered CeO2 doped ZrO2 ceramics were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDS) analysis, and X-ray diffraction (XRD) respectively. X-ray diffraction for samples sintered at 1550 °C for 4h revealed that the zirconia ceramics have a tetragonal phase structure. The addition of CeO2 can raise the content of the tetragonal phase, but the minor monoclinic phase exists even at the CeO2 content of 10 mol%. The effect of dopant concentration on the lattice parameter, average primary crystallite size and micro-strain was studied. Relative densities for CeO2 doped ZrO2 bulk ceramics varied between 95% and 99 %, depending on the CeO2 addition.


Author(s):  
Hasan A. Hadi ◽  
Raid A. Ismail ◽  
Nadir F. Habubi

Porous silicon (PS) has been fabricated by Photo-electrochemical etching. Porous silicon was anodized on n-type Si in light using a current density of 20 mA/cm2 for 10 min. The porous structure formation was confirmed using XRD and AFM studies. The root mean square (RMS) roughness of the Porous silicon layer is found to be around 47.5 nm and the ten point height was 317 nm. The average of pores diameter was 419.98nm, and the grain growth is columnar with a (211) preferred orientation. The grain size of the PS was estimated from the Scherer’s formula and found to be 73 nm. All the properties of the porous silicon layer, such as porosity and the thickness depend on the anodization parameters. The porosity (P) was approximately 77%. The thickness of the layer formed during an anodization in constant current was 3.54 nm in gravimetric method, while its value was 1.77 nm by using the theoretical relation.


2021 ◽  
Vol 4 (1) ◽  
pp. 7
Author(s):  
Lalu A. Didik ◽  
Muh. Wahyudi

The synthesis of CuCrO2 crystals by mixing CuO and Cr2O3 has been carried out using the solid reaction method at a temperature of 1200 0C. The characterization of the structure used XRD and analyzed using GSAS software. The results of characterization using XRD showed that no other phase occurred. This is evidenced by the absence of other phases from the results of refinement of measurement data with reference data and a value of χ 2 which is 1.222. The lattice parameter values resulting from the refinement of the CuCrO2 X-ray diffraction pattern are a = b = 2.9715 Å and c = 17.1104 Å with a cell volume of 130.584 Å 3. In addition to the lattice parameter values, the distance between atoms was also obtained, both Cu - O, Cr - Cr, and Cr - O.


2018 ◽  
Vol 4 (4) ◽  
pp. 68 ◽  
Author(s):  
Karolina Jurkiewicz ◽  
Mirosława Pawlyta ◽  
Andrzej Burian

Transmission electron microscopy and neutron or X-ray diffraction are powerful techniques available today for characterization of the structure of various carbon materials at nano and atomic levels. They provide complementary information but each one has advantages and limitations. Powder X-ray or neutron diffraction measurements provide structural information representative for the whole volume of a material under probe but features of singular nano-objects cannot be identified. Transmission electron microscopy, in turn, is able to probe single nanoscale objects. In this review, it is demonstrated how transmission electron microscopy and powder X-ray and neutron diffraction methods complement each other by providing consistent structural models for different types of carbons such as carbon blacks, glass-like carbons, graphene, nanotubes, nanodiamonds, and nanoonions.


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