arXiv subjects

Yu. A. Koksharov

Publications and source records attributed to Yu. A. Koksharov.

4 recordsLinked to original sources

arXiv2022

Electrostatic repulsion between a uncharged or slightly charged conductor and a point charge

A counterintuitive effect of a repulsion between uncharged and charged conductors is considered. Our numerical calculations prove this effect for various axially symmetric systems of a neutral conductor in an electric field of a point charge. The presence of a cavity in the conductor is very important for the repulsion effect. Our simple analytical model explains this effect in terms of specific spatial positions of induced charges.

physics.class-ph↗

arXiv2020

Sources of E, D, B, H in electro- and magnetostatics: critical comments

A critical analysis of teaching approaches to the issue of sources of electrostatic and magnetostatic fields is carried out. Incorrect statements are discussed and their reasons are indicated, in particular, the ambiguity of terminology and going beyond formulas applicability. Unified approach to the study of electromagnetic static field sources based on the Helmholtz theorem is recommended.

physics.ed-ph↗

arXiv2014

Molecular magnetism and crystal field effects in the Kondo system Ce$_3$Pd$_{20}$(Si,Ge)$_6$ with two Ce sublattices

The unusual electronic and magnetic properties of the systems Ce$_3$Pd$_{20}$T$_6$ (T = Ge, Si) with two non-equivalent Ce positions are discussed. The logarithmic growth of resistance for both the systems confirms the presence of the Kondo effect in the two respective temperature ranges. The two-scale behavior is explained by consecutive splitting of Ce ion levels in the crystal field. The effects of the frustration caused by the coexistence of the different positions of cerium are treated, which may also significantly enhance the observed values of specific heat. A model of "molecular magnetism" with Ce2 cubes is developed.

cond-mat.str-el↗

arXiv2013

Magnetism and Verwey transition in magnetite nanoparticles in thin polymer film

Magnetic and structural properties of magnetite nanoparticles stabilized in polyvinyl-alcohol thin films are investigated by using X-ray diffraction (XRD), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR) and static magnetometry techniques. The nanoparticles have well-defined crystallinity, and are superparamagnetic at room temperature. Their size distribution is characterized by the distinct log-normal law (with average diameters near 5-7 nm) and slight maximum near 70-80 nm. The EPR spectra and static magnetization data demonstrated pronounced anomalies in the interval between 130 K (corresponding to Verwey transition) and 200 K. The experimental data obtained can be understood on the basis of the half-metallic electronic structure, complex temperature behavior of the magnetic anisotropy, along with effects of "weak magnetic-electron" sublattice of magnetite.

cond-mat.mtrl-sci↗