Lattice-parameter misfits between the γ and γ′ phases in single crystals of nickel superalloys

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

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Effect of Sintering Parameter on the Microstructure and Electrical Properties for Bi2Se3 Topological Insulator Crystals

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.709.172 ◽

2013 ◽

Vol 709 ◽

pp. 172-175

Author(s):

Li Lv ◽

Min Zhang ◽

Li Qin Yang ◽

Xin Sheng Yang ◽

Yong Zhao

Keyword(s):

Electrical Properties ◽

Cooling Rate ◽

Single Crystals ◽

Carrier Concentration ◽

Topological Insulator ◽

Layered Structure ◽

Phase Structure ◽

Lattice Parameter ◽

Holding Time ◽

Type Conductivity

Single crystals of Bi2Se3 topological insulators have been prepared though melt-grown reaction. The sintering parameters of holding time and cooling rate obviously affect the phase structure and electrical properties. The samples with layered structure can be perpendicular cleaved with (0 0 L) axis. All the samples show n-type conductivity caused by the existence of Se vacancies. For low cooling rate, more Se atoms anti-occupy Bi lattice sites, which decreases c-axis lattice parameter and increases carrier concentration n; high cooling rate increases c and decreases n because of less Se atoms occupying Bi lattice sites. Increasing holding time firstly decreases the ratio of Se atoms occupying Bi lattice sites and then increases it, which gives rise to c firstly increase then decrease and n firstly decrease then increase.

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Graded X-ray Optics for Synchrotron Radiation Applications

Journal of Synchrotron Radiation ◽

10.1107/s0909049597019043 ◽

1998 ◽

Vol 5 (3) ◽

pp. 239-245 ◽

Cited By ~ 9

Author(s):

A. Erko ◽

M. Veldkamp ◽

W. Gudat ◽

N. V. Abrosimov ◽

S. N. Rossolenko ◽

...

Keyword(s):

Synchrotron Radiation ◽

Magnetron Sputtering ◽

Single Crystals ◽

Theoretical Data ◽

Lattice Parameter ◽

Structure And Properties ◽

Czochralski Technique ◽

Spectral Measurements ◽

Optical Elements ◽

X Ray

Using X-ray diffractometry and spectral measurements, the structure and properties of graded X-ray optical elements have been examined. Experimental and theoretical data on X-ray supermirrors, which were prepared by the magnetron sputtering technique using precise thickness control, are reported. Measurements on graded aperiodic Si1−x Ge x single crystals, which were grown by the Czochralski technique, are also presented. The lattice parameter of such a crystal changes almost linearly with increasing Ge concentration. The measurements indicate that Si1−x Ge x crystals with concentrations up to 7 at.% Ge can be grown with a quality comparable to that of pure Si crystals.

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Absolute measurement of lattice parameter in single crystals and epitaxic layers on a double-crystal X-ray diffractometer

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767305004496 ◽

2005 ◽

Vol 61 (3) ◽

pp. 301-313 ◽

Cited By ~ 9

Author(s):

M. Fatemi

Keyword(s):

Single Crystals ◽

Absolute Measurement ◽

Lattice Parameter ◽

Double Crystal ◽

X Ray

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Oxygen Concentration Determination in Silicon Single Crystals by Precision Lattice Parameter Measurement

Advances in X-ray Analysis ◽

10.1154/s0376030800014890 ◽

1990 ◽

Vol 34 ◽

pp. 577-586

Author(s):

H. Ohmori ◽

M. Tomita ◽

N. Tsuchiya ◽

Y. Matsushita

Keyword(s):

Single Crystals ◽

Oxygen Concentration ◽

Diffraction Method ◽

Lattice Parameter ◽

Peak Position ◽

Silicon Wafers ◽

Parameter Measurement ◽

Lattice Parameter Measurement ◽

Precise Adjustment ◽

Fitting In

AbstractPrecision lattice parameter measurement by the X-ray diffraction method of Bond [1] has been examined as a substitutional method for IR in determining the oxygen concentration in silicon single crystals. Asymmetric 444 CuKai reflections were measured for undoped (100) oriented silicon wafers to obtain the correlation curve between the silicon lattice parameter and oxygen concentration. Precise adjustment of the optical system and computer fitting in determining the peak position allow a minute lattice dilation of silicon due to oxygen to be detected by the Bond method. The precision of this measurement system was of the order of 10-6. The lattice expansion of silicon by dissolved oxygen was determined to be at the rate of 3.2X10-24 atoms of oxygen per cm3. Furthermore, the oxygen concentrations of heavily Sb-doped silicon wafers were determined nondestructively.

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Lattice Parameter Deviation of InP Single Crystals Grown by the Horizontal Bridgman Method under Controlled Phosphorus Vapor Pressure

Japanese Journal of Applied Physics ◽

10.1143/jjap.40.2219 ◽

2001 ◽

Vol 40 (Part 1, No. 4A) ◽

pp. 2219-2220

Author(s):

Atsushi Shimizu ◽

Jun-ichi Nishizawa ◽

Yutaka Oyama ◽

Ken Suto

Keyword(s):

Vapor Pressure ◽

Single Crystals ◽

Lattice Parameter ◽

Bridgman Method ◽

Parameter Deviation

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Lattice-parameter measurements of PbHPO4 single crystals by the ratio method

Journal of Applied Crystallography ◽

10.1107/s0021889883011188 ◽

1983 ◽

Vol 16 (6) ◽

pp. 623-628 ◽

Cited By ~ 7

Author(s):

J. Horváth

Keyword(s):

Phase Transition ◽

Single Crystals ◽

Ferroelectric Phase Transition ◽

Ferroelectric Phase ◽

Lattice Parameter ◽

Ratio Method ◽

Monoclinic Crystal System ◽

Monoclinic Crystal ◽

Temperature Dependences ◽

Crystal Lattice Parameters

Temperature dependences of PbHPO4 single-crystal lattice parameters were measured by the ratio method in the range 158–421 K. Below the ferroelectric phase transition (T c = 310 K) lattice parameter b increases non-linearly with decreasing temperature while all others decrease linearly. The ratio method was generalized to the monoclinic crystal system for this purpose.

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