Contribution of Mechanical Stresses to the Surface Relief Formation Under Laser Irradiation of Semiconductors

Russian Physics Journal - The paper considers the effect of elastic stresses arising under pulsed laser irradiation of epitaxial layers of CdxHg1–xTe solid solutions on the formation of a...     

Generation of Surface Defects in Epitaxial Cd x Hg1–xTe Layers by Soft X-ray Radiation of Laser Plasma

Russian Physics Journal - The possibility is demonstrated of a selective action of soft X-ray radiation on atoms of an individual element on the surface of a crystal constructed of atoms of several...     

Stress relaxation in CdHgTe/CdTe heterostructures

Based on our analysis of the results of measurements of elastic deformation in Cd_xHg_1–xTe/CdTe heterostructures it is shown that the degree of relaxation of the crystal lattice for Cd_0.2Hg_0.8Te films 1 µm thick with a working temperature of 273 K is 0.8766, which supports the idea of almost full relaxation of the mismatch stress for such thicknesses of A₂B₆ films.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 112–114, August, 1995.     

Defect profiles in graded band-gap layers of <Emphasis Type="Italic">P</Emphasis>-HgCdTe heteroepitaxial structures under ion-beam etching

The results of investigations into spatial distribution of donors in p-HgCdTe graded band-gap layers with various composition profiles in the near-surface layer upon ion-beam etching are reported. It is found that the depth of the resulting n⁺-layer is weakly dependent on the conditions of ion-beam etching and composition of material of the surface and is about 0.5–1 μm. The electron density in the n⁺-layer on the surface is observed to increase with time of beam etching. It is shown that the conditions of ion-beam etching and the composition of the near-surface region significantly affect only the depth of the foregoing layer with low electron density. Analysis of experimental data shows that the process of ion-bean etching in p-HgCdTe heteroepitaxial structures with a composition gradient in the near-surface region is different from etching in HgCdTe homogeneous epitaxial structures and crystals. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 51–56, September, 2008.     

Elasticity moduli of Cd<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Hg<Subscript>1–<Emphasis Type="Italic">x</Emphasis></Subscript>Te solid solutions

Results of investigations into the temperature dependences (4.2–300 K) of the low-frequency ultrasound velocity in Cd _x Hg_1–x Te single crystals are presented. The elastic moduli and the Debye temperatures are calculated for different solid solution compositions. Based on the data obtained, possible stresses are estimated on the heteroboundary of the materials with a number of substrates.     

Magnetic properties of maghemite nanoparticles

Magnetic particles of maghemite (spinel γ-Fe₂O₃) are synthesized by means of aerosol pyrolysis, making it possible to produce chemically uniform highly-dispersed single-phase materials. The magnetic properties of synthesized particles for temperatures ranging from helium temperature up to room temperature and higher are investigated using a SQUID magnetometer. The experimental curves are compared to the results from calculations performed by the Monte Carlo method. It is found that the Curie temperature is lower for γ-Fe₂O₃ nanoparticles than for bulk samples. Several parameters of the material are estimated by comparing the experimental and calculated results.