Crystal Structures of Epitaxially Grown Fe16N2 Single Crystal Films with Giant Magnetic Moments

1992 ◽  
Vol 263 ◽  
Author(s):  
Matahiro Komuro ◽  
Hiroyuki Hoshiya ◽  
Hiroaki Takahashi ◽  
Katsuya Mitsuoka ◽  
Yutaka Sugita

ABSTRACTLattice parameters and crystal orientation for Fe1 6.N2 were determined by an X-ray diffraction method using a three axes goniometer. The lattice parameters of the a-axis and c-axis(a0, c0.) are 5.71 !A and 6.33 !A, respectively. The co corresponds to that of In0, 2,Gao.,s As substrates. Crystal orientation between Fe1 5.N2. films and Ino.,2Gao.,8 As is Fe1 0N2(001)//In0 2.Ga0.2 As(1001) and Fe1 0.N2.(100)//In02Ga0.6As(100). Intensity ratios for these diffraction peaks are in good agreement with calculated values proposed by Jack.

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.


1983 ◽  
Vol 27 ◽  
pp. 53-60 ◽  
Author(s):  
T. C. Huang ◽  
W. Parrish ◽  
G. Lim

AbstractThe combined derivative method (accompanying paper) was tested with a large number of experimental patterns to illustrate its use in various difficult problems commonly arising in peak search analysis of X-ray diffraction data. Patterns obtained with various step sizes, resolution, counting statistical noise, and profile widths were used. The precision in 2θ determination and overlap resolution are in good agreement with those previously obtained from calculated profiles, raise identification of noise as diffraction peaks was eliminated by using a convolution range proportional to the full width at half maximum. Peak search results (both 2θ and intensity) were also compared to those obtained by profile fitting to illustrate the different characteristics of these two methods.


2019 ◽  
Vol 33 (23) ◽  
pp. 1950271 ◽  
Author(s):  
Y. I. Aliyev ◽  
Y. G. Asadov ◽  
A. O. Dashdemirov ◽  
R. D. Aliyeva ◽  
T. G. Naghiyev ◽  
...  

The Ag[Formula: see text]Cu[Formula: see text]Se and Ag[Formula: see text]Cu[Formula: see text]Se compounds have been synthesized and grown as single crystals. High-temperature X-ray diffraction method was used to study polymorphic transformations. It is shown that the Ag[Formula: see text]Cu[Formula: see text]Se crystals of high-temperature FCC modification are decomposed into Ag2Se and AgCuSe when the temperature decreases below T = 488 K and Ag[Formula: see text]Cu[Formula: see text]Se is decomposed into Cu2Se and AgCuSe when the temperature decreases below T = 540 K. Transformations in both compounds are reversible. Crystalline parameters are obtained and the temperature dependence of the lattice parameters for each phase is built.


2014 ◽  
Vol 660 ◽  
pp. 942-946
Author(s):  
Mohamad Firdaus Abdul Wahid ◽  
C.M. Mardziah ◽  
Koay Mei Hyie ◽  
N.R. Nik Roselina

Hydroxyapatite was prepared by using precipitation method. The substitution of zinc ions in hydroxyapatite structure was studied by several characterization techniques. Several concentration of zinc ions were substituted into hydroxyapatite. Characterization technique such as X-ray diffraction method was used to study the phase changes and the lattice parameters with the addition of zinc. Field emission scanning electron microscopy was used to examine the influence of zinc on the crystal size and the morphology of the as-synthesized powders. Based on X-ray diffraction result, the addition of zinc affects the lattice parameters and phase. The result showed that zinc ions were substituted in the structure. As zinc substitution increased, the lattice parameters a and c decreased. The crystal shape of hydroxyapatite without zinc ions was regular shapes while hydroxyapatite with zinc ions was irregular and also tends to agglomerates with single particle was calculated about 28 - 34 nm .


2017 ◽  
Vol 647 (1) ◽  
pp. 169-178 ◽  
Author(s):  
I. A. Zaluzhnyy ◽  
R. P. Kurta ◽  
A. P. Menushenkov ◽  
B. I. Ostrovskii ◽  
I. A. Vartanyants

1991 ◽  
Vol 230 ◽  
Author(s):  
Joseph Pellegrino ◽  
S. Qadri ◽  
W. Tseng ◽  
W. R. Miller ◽  
J. Comas

AbstractIn this work we examine the physical properties for the superlattice system (GaAs)n1 (AlAs)n2/GaAs(100) for low values of n1 and n2, i.e., n1 = n2 = 3, 6, 12. Normal, interrupted growth, and migration enhanced epitaxy (MEE) growth techniques were used to grow the superlattice structures in a molecular beam epitaxy system. X-ray diffraction spectra were obtained, and the major and satellite peak positions were analyzed to obtain the superlattice periodicity. An analysis of the major diffraction peaks and their associated satellites produced superlattice periodicity in good agreement with theory. Diffraction peaks were also observed in regions adjacent to the primary diffraction peaks which did not occur in the expected satellite positions. An analysis of these peaks relative to the primary peak indicate periodicities corresponding to layer thickness greater than the intended period. One possible cause for these periodicities is growth conditions that exist during the growth of the superlattice which result in the deposition of fractional monolayers. In this study we present results which suggest that an arsenic-deficient growth condition may be a contributing factor in the deposition of fractional monolayers.


2020 ◽  
Vol 4 (1) ◽  
pp. 24-30
Author(s):  
Muhamad Ragil Setiawan ◽  
Rahmat Nawi Siregar

This study aims to determine the mineral content and crystal structure of schist rocks in South Lampung. The method used in this research is the X-ray diffraction method to see the lattice parameters and the crystal structure of the schist rocks. Based on data processing, information was obtained that two main minerals were found, namely quartz and albite minerals. In conclusion, the Albit minerals found in the two samples of rock crystal schists in South Lampung have the same crystal structure and lattice parameters, while the quartz minerals from the two samples have different crystal structures and lattice parameters. Keywords: Lampung, Schis, XRD, Crystal Structure


Author(s):  
Ali Taha Saleh ◽  
Dheyaa Alameri

A novel two-step methodology delivering zinc into the structure of β-tricalcium phosphate (β-TCP) has been investigated. Incorporating wet precipitation of calcium-deficient apatite [Ca9-xZnx(HPO4)(PO4)5(OH)] (x = 0.00–1.00 mol) using a microwave-assisted process followed by two-hour calcination at 1000 °C has been conducted to generate a ratio of 1.48 of Zn doped β-TCP. The products were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectrometer, and field emission scanning electron microscope (FESEM). Our results confirmed that the product was crystalline Zn2+-doped β-tricalcium phosphate. The incorporation of Zn+2 into the β-TCP lattice resulted in a shifting of diffraction peaks to higher 2θ values, which were attributed to the substitution of larger-sized Ca+2 ions with smaller-sized Zn2+ ions. A reduction in the intensity of the XRD peaks was also observed due to the reduction in the degree of crystallinity of the samples. Lattice parameters along the a and c-axis showed a gradual decrease in length with an increase in the amount of Zn2+ doping. This decrease was attributed to the replacement of Ca+2 ion by the smaller-sized Zn2+ ions. The microstructure of the powders consisted of microscale aggregates fused together. EDX analysis of all samples showed that the Zn2+ doping had successfully taken place and the amount of Zn2+ present in the samples was in good agreement with the theoretical values.


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