Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Analysis Of Clusterization Of C70 Molecules In Benzene Solutions Prepared By Various Methods, U. Makhmanov, O. Ismailova, A. Kokhkharov, S. Bakhramov Sep 2018

Analysis Of Clusterization Of C70 Molecules In Benzene Solutions Prepared By Various Methods, U. Makhmanov, O. Ismailova, A. Kokhkharov, S. Bakhramov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

Self-assembling features of molecules of C70 in benzene solution prepared in two various ways – equilibrium and non-equilibrium – has been investigated experimentally by method of high-resolution transmission electron microscopy. It was demonstrated, that the formation of densely packed monomolecular fullerene aggregates with a diameter of not more than 30 nm in solutions prepared by the equilibrium method (without the use of external mechanical influences on solution). In the case of solutions C70, which were prepared by the non-equilibrium method (stirring of solution of C70 by a mechanical rotator), large quasispherical aggregates of nanoporous structure with …


Electronic Specific-Heat Anomalies In High-TC Cuprates, S. Dzhumanov, E. Karimboev, B. Yavidov Sep 2018

Electronic Specific-Heat Anomalies In High-TC Cuprates, S. Dzhumanov, E. Karimboev, B. Yavidov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this work, we study the electronic specific heat $C_e(T)$ of underdoped to overdoped high-$T_c$ cuprates, and identify the nature of anomalies in $C_e(T)$ at the superconducting transition temperature $T_c$ and at temperatures above $T_c$. The doped cuprate superconductor is considered as a multi-carrier model system which is composed of different types of charge carriers. The normal-state electronic specific heat $C_n(T)$ of high-$T_c$ cuprates below a characteristic pseudogap (PG) temperature $T^*$ is calculated taking into account three contributions coming from the excited components of Cooper pairs, the ideal Bose-gas of incoherent Cooper pairs and the unpaired carriers in the impurity …


Electron Exchange Between Impurity Centers Of Tin In Pbs And Pbse, S. Zaynabiddinov, K. Bobokhujaev Sep 2018

Electron Exchange Between Impurity Centers Of Tin In Pbs And Pbse, S. Zaynabiddinov, K. Bobokhujaev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

Electron exchange between neutral and doubly ionized U-minus centers of tin in par-tially compensated solid solutions Pb1-xSnxS and Pb1-xSnxSe has been investigated using 119mmSn(119mSn) emission Mössbauer spectroscopy. The activation energy of the process for Pb1-xSnxS solid solutions is 0.11 ± 0.02 eV and is comparable to the depth of energy levels of tin in the PbS band gap, while the activation energy of this process for Pb1-xSnxSe solid solutions is comparable to the activation energy of donor U-minus centers …