arXiv subjects

Marko Kuveždić

Publications and source records attributed to Marko Kuveždić.

4 recordsLinked to original sources

arXiv2025

Electronic structure property relationship in glassy Ti-Zr-Nb-(Cu,Ni,Co)

In this work we revisit vast amount of existing data on physical properties of Ti-Zr-Nb-(Cu,Ni,Co) glassy alloys over a broad range of concentrations (from the high entropy range to that of conventional Cu-, Ni- or Co-rich alloys). By using our new approach based on total content of late transition metal(s), we derive a number of physical parameters of a hypothetical amorphous TiZrNb alloy: lattice parameter $a = (3.42 \pm 0.02)$Å, Sommerfeld coefficient $γ= 6.2\,$mJ/mol$\,$K$^2$, density of states at $N(E_F) = 2.6\,(\text{at eV})^{-1}$, magnetic susceptibility $(2.00 \pm 0.05)\,$mJ/T$^2\,$mol, superconducting transition temperature $T_c = (8 \pm 1)\,$K, upper critical field $μ_0 H_{c2}(0) = (20 \pm 5)\,$T, and coherence length $ξ(0) = (40 \pm 3)\,$Å. We show that our extrapolated results for amorphous TiZrNb alloy would be similar to that of crystalline TiZrNb, except for superconducting properties (most notably the upper critical field $H_{c2}(0)$), which might be attributed to the strong topological disorder of the amorphous phase. Also, we offer an explanation of the discrepancy between the variations of $T_c$ with the average number of valency electrons in neighboring alloys of 4d transition metals and some high entropy alloys. Overall, we find that our novel method of systematic analysis of results is rather general, as it can provide reliable estimates of the properties of any alloy which has not been prepared as yet.

cond-mat.mtrl-sci↗

arXiv2024

Spin-Reorientation-Driven Linear Magnetoelectric Effect in Topological Antiferromagnet Cu$_3$TeO$_6$

The search for new materials for energy-efficient electronic devices has gained unprecedented importance. Among the various classes of magnetic materials driving this search are antiferromagnets, magnetoelectrics, and systems with topological spin excitations. Cu$_3$TeO$_6$ is a material that belongs to all three of these classes. Combining static electric polarization and magnetic torque measurements with phenomenological simulations we demonstrate that magnetic-field-induced spin reorientation needs to be taken into account to understand the linear magnetoelectric (ME) effect in Cu$_3$TeO$_6$. Our calculations reveal that the magnetic field pushes the system from the nonpolar ground state to the polar magnetic structures. However, nonpolar structures only weakly differing from the obtained polar ones exist due to the weak effect that the field-induced breaking of some symmetries has on the calculated structures. Among those symmetries is the $PT$ ($\overline{1}'$) symmetry, preserved for Dirac points found in Cu$_3$TeO$_6$. Our findings establish Cu$_3$TeO$_6$ as a promising playground to study the interplay of spintronics-related phenomena.

cond-mat.str-el↗

arXiv2019

Change of electronic properties on transition from high-entropy to Ni-rich (TiZrNbCu)(1-x)Ni(x) alloys

We present results of comprehensive study of electronic properties of (TiZrNbCu)(1-x)Ni(x) metallic glasses performed in broad composition range x encompassing both, high entropy (HE) range, and conventional Ni-base alloy concentration range, x >= 0.35. The electronic structure studied by photoemission spectroscopy and low temperature specific heat (LTSH) reveal a split-band structure of density of states inside valence band with d-electrons of Ti, Zr, Nb and also Ni present at Fermi level N(E_F), whereas LTSH and magnetoresistivity results show that variation of N(E_F) with x changes in Ni-base regime. The variation of superconducting transition temperatures with x closely follows that of N(E_F). The electrical resistivities of all alloys are high and decrease with increasing temperature over most of explored temperature range, and their temperature dependence seems dominated by weak localization effects over a broad temperature range (10-300 K). The preliminary study of Hall effect shows positive Hall coefficient that decreases rapidly in Ni-base alloys.

cond-mat.mtrl-sci↗

arXiv2017

Semimetallic and charge-ordered $α$-(BEDT-TTF)$_2$I$_3$: on the role of disorder in dc transport and dielectric properties

$α$-(BEDT-TTF)$_2$I$_3$ is a prominent example of charge ordering among organic conductors. In this work we explore the details of transport within the charge-ordered as well as semimetallic phase at ambient pressure. In the high-temperature semimetallic phase, the mobilities and concentrations of both electrons and holes conspire in such a way to create an almost temperature-independent conductivity as well as a low Hall effect. We explain these phenomena as a consequence of a predominantly inter-pocket scattering which equalizes mobilities of the two types of charge carriers. At low temperatures, within the insulating charge-ordered phase two channels of conduction can be discerned: a temperature-dependent activation which follows the mean-field behavior, and a nearest-neighbor hopping contribution. Together with negative magnetoresistance, the latter relies on the presence of disorder. The charge-ordered phase also features a prominent dielectric peak which bears a similarity to relaxor ferroelectrics. Its dispersion is determined by free-electron screening and pushed by disorder well below the transition temperature. The source of this disorder can be found in the anion layers which randomly perturb BEDT-TTF molecules through hydrogen bonds.

cond-mat.str-el↗