Strip Microheater for Investigation of Thermal Conductivity Coefficient Using the 3-Omega Method

This paper discusses the theoretical information and the method of forming strip micro-heaters using electron lithography in order to study the thermal conductivity coefficient using the 3-omega method.Исследование выполнено при финансовой поддержке стипендии Президента Российской Федерации (СП-2235.2019.1)

Band structure of ruthenate superconductors

We investigate the band structure of ruthenates using the first-principles method of density functional theory (DFT). We calculated the band structure and density of states at the Fermi level for superconductors Ba2YRuO6 and Sr2YRuO6. Our calculations show that the maximum critical superconducting transition temperature Tc=93K can be obtained for Ba2YRuO6

Preparation, magnetic studies and band structure calculation of NiFe2O4 nanoparticles

We have undertaken a comprehensive theoretical study of the band structure, density of states, dependence of the Curie point and saturation magnetization on the size of NiFe2O4 nanoparticles prepared by the conventional ceramic method. Commercially available NiFe2O4 powder was first annealed in an oxygen environment in a furnace at 1100oC for 3h. The X-ray diffraction pattern indicated that the sample was single-phase at this stage. The average grain size estimated by scanning electron microscopy (SEM) was in the range of 300 to 350nm. The magnetic behavior of the sample at room temperature was studied by means of a superconducting quantum interference device (SQUID). The Curie temperature of the nickel ferrite powder was measured using an LCR meter. The measurement of the Curie temperature and saturation magnetization indicated that a decrease in the grain size leads to a decrease in the Curie temperature and in the saturation magnetization. The small value of saturation magnetization was attributed to a spin-glass-like surface layer on the nanocrystalline nickel ferrite with a ferrimagnetically aligned core (H.Nathani and S.Gubbala 2004 J.Mater. Sci. and Engin. B 111 95). Good agreement was obtained between theory and experimental results

The electronic properties of new Fe-based superconductors

We investigate the band structure of Fe-based superconductors using the first-principle method of density-functional theory. We calculated the band structure and the density of states at the Fermi level for ReFeAsO (Re = Sm, Dy, Ho, Er) superconductors. Our calculations indicate that the maximum critical superconducting transition temperature Tc will be observed for compounds with Sm and Er. We predict that Tc=60K for ErFeAsO

Armed forces of Byzantium in the beginning of XIV century (principles to complete army and fighting employment on the basis of an example - the battle at Apros)

The article gives a clear account of the problem of evolution of the military organization of late Byzantium. Using as a research basis the analysis of the Byzantium battlearray in fight at Aprose – the central battle of the military conflict with a Catalan army, the author considers that reorganization of imperial armed forces resulted in transformation into an army of mercenaries. Thus, in the beginning of XIV century 2/3 of the Byzantium army consisted of contingents of mercenaries

Line-shape analysis of optical spectra in metaphosphate glasses doped with erbium ions

Erbium-doped phosphate glasses of a well known composition are used to study the line-shape contributions in optical spectra of Er3+ ions involving electronic transitions between the excited I-4(13/2) state and the ground I-4(15/2) state multiplets. The absorption and emission spectra are measured for various M(PO3)(2) (where M = Sr, Ba, Ca, Zn and Cd) host glasses in a wide temperature interval (from 10 to 300 K). The line-shape analysis is performed using the cluster-like model of erbium surrounding thus allowing the calculation of the contribution to the magnitude of each individual Stark component. The magnitude distribution among the Stark components correctly reproduces the line-shape behavior in absorption and emission spectra within the investigated temperature range. (c) 2005 Elsevier B.V. All rights reserved

Line-shape analysis of optical spectra in metaphosphate glasses doped with erbium ions

Erbium-doped phosphate glasses of a well known composition are used to study the line-shape contributions in optical spectra of Er3+ ions involving electronic transitions between the excited I-4(13/2) state and the ground I-4(15/2) state multiplets. The absorption and emission spectra are measured for various M(PO3)(2) (where M = Sr, Ba, Ca, Zn and Cd) host glasses in a wide temperature interval (from 10 to 300 K). The line-shape analysis is performed using the cluster-like model of erbium surrounding thus allowing the calculation of the contribution to the magnitude of each individual Stark component. The magnitude distribution among the Stark components correctly reproduces the line-shape behavior in absorption and emission spectra within the investigated temperature range