Searcharxiv⌕ Search

arXiv subjects

D. V. Marinin

Publications and source records attributed to D. V. Marinin.

10 recordsLinked to original sources
arXiv2021

Crystal chemistry criteria of the existence of spin liquids on the kagome lattice

The structural-magnetic models of 25 AFM kagome cuprates similar to herbertsmithite (ZnCu3(OH)6Cl2) - a perspective spin liquid - have been calculated and analyzed. Main correlations between the structure and magnetic properties of these compounds were revealed. It has been demonstrated that, in all AFM kagome cuprates, including herbertsmithite, there exists the competition between the exchange interaction and the antisymmetric anisotropic exchange one (the Dzyaloshinskii-Moriya interaction), as magnetic ions are not linked to the center of inversion in the kagome lattice. This competition is strengthened in all the kagome AFM, except herbertsmithite, by one more type of the anisotropy (duality) of the third in length J3 magnetic couplings (strong J3(J12) next-to-nearest-neighbor couplings in linear chains along the triangle edges and very weak FM or AFM J3(Jd) couplings along the hexagon diagonals). The above couplings are crystallographically identical, but are divided to two types of different in strength magnetic interactions. The existence of duality of J3 couplings originated from the structure of the kagome lattice itself. Only combined contributions of dual J3 couplings with anisotropic DM interactions are capable to suppress frustration of kagome AFM. It has been demonstrated that the possibility of elimination of such a duality in herbertsmithite, which made it a spin liquid, constitutes a rare lucky event in the kagome system. Three crystal chemistry criteria of the existence of spin liquids on the kagome lattice have been identified: first, the presence of frustrated kagome lattices with strong dominant antiferromagnetic nearest-neighbor J1 couplings competing only with each other in small triangles; second, magnetic isolation of these frustrated kagome lattices; and third, the absence of duality of the third in length J3 magnetic couplings.

cond-mat.mtrl-sci↗
arXiv2018

Antiferromagnetic spin-frustrated layers of corner-sharing Cu4 tetrahedra on the kagome lattice in volcanic minerals Cu5O2(VO4)2(CuCl), NaCu5O2(SeO3)2Cl3, and K2Cu5Cl8(OH)4 2H2O

The objective of the present work was to analyze the possibility of realization of quantum spin liquid in three volcanic minerals - averievite (Cu5O2(VO4)2(CuCl)), ilinskite (NaCu5O2(SeO3)2Cl3), and avdononite (K2Cu5Cl8(OH)4 2H2O - from the crystal chemistry point of view. Based on the structural data, the sign and strength of magnetic interactions have been calculated and the geometric frustrations serving as the main reason of the existence of spin liquids have been investigated. According to our calculations, the magnetic structures of averievite and ilinskite are composed of antiferromagnetic (AFM) spin-frustrated layers of corner-sharing Cu4 tetrahedra on the kagome lattice. However, the direction of nonshared corners of tetrahedra is different in them. The oxygen ions centering the OCu4 tetrahedra in averievite and ilinskite provide the main contribution to the formation of AFM interactions along the tetrahedra edges. The local electric polarization in averievite and the possibility of spin configuration fluctuations due to vibrations of tetrahedra-centering oxygen ions have been discussed. The existence of structural phase transitions accompanied with magnetic transitions was assumed in ilinskite because of the effect of a lone electron pair by Se4+ ions. As was demonstrated through comparison of averievite and avdoninite, at the removal of centering oxygen ions from tetrahedra, the magnetic structure of the pyrochlore layer present in averievite transformed into an openwork curled net with large cells woven from corner-sharing open AFM spin-frustrated tetrahedra ('butterflies'} in avdoninite.

cond-mat.mtrl-sci↗
arXiv2018

Spin-Frustrated Pyrochlore Chains in the Volcanic Mineral Kamchatkite (KCu3OCl(SO4)2)

Search of new frustrated magnetic systems is of a significant importance for physics studying the condensed matter. The platform for geometric frustration of magnetic systems can be provided by copper oxocentric tetrahedra (OCu4) forming the base of crystalline structures of copper minerals from Tolbachik volcanos in Kamchatka. The present work was devoted to a new frustrated antiferromagnetic - kamchatkite (KCu3OCl(SO4)2). The calculation of the sign and strength of magnetic couplings in KCu3OCl(SO4)2 has been performed on the basis of structural data by the phenomenological crystal chemistry method with taking into account corrections on the Jahn-Teller orbital degeneracy of Cu2. It has been established that kamchatkite (KCu3OCl(SO4)2) contains AFM spin-frustrated chains of the pyrochlore type composed of cone-sharing Cu4 tetrahedra. Strong AFM intrachain and interchain couplings compete with each other. Frustration of magnetic couplings in tetrahedral chains is combined with the presence of electric polarization.

cond-mat.mtrl-sci↗
arXiv2016

Frustrated antiferromagnetic spin chains of edge-sharing tetrahedra in volcanic minerals K3Cu3(Fe0.82Al0.18)O2(SO4)4 and K4Cu4O2(SO4)4MeCl

The calculation of the sign and strength of magnetic interactions in two noncentrosymmetric minerals (klyuchevskite, K3Cu3(Fe0.82Al0.18)O2(SO4)4 and piipite, K4Cu4O2(SO4)4Cu0.5Cl) has been performed based on the structural data. As seen from the calculation results, both minerals comprise quasi-one-dimensional frustrated antiferromagnets. They contain frustrated spin chains from edge-sharing Cu4 tetrahedra with strong antiferromagnetic couplings within chains and very weak ones between chains. Strong frustration of magnetic interactions is combined with the presence of the electric polarization in tetrahedra chains in piipite. The uniqueness of magnetic structures of these minerals caused by peculiarities of their crystal structures has been discussed. Keywords: Frustrated quasi-one-dimensional antiferromagnets, tetrahedral spin chains, klyuchevskite K3Cu3(Fe0.82Al0.18)O2(SO4)4, piypite K4Cu4O2(SO4)4MeCl

cond-mat.mtrl-sci↗
arXiv2016

Possibility of Emergence of Chiral Magnetic Soliton in Hexagonal Metal Formate [NH4][M(HCOO)3] with M2+ = Mn, Fe, Co, and Ni and KCo(HCOO)3

Search of chiral magnetic solitons on the basis of the data on the crystal structure is important from both fundamental and technological points of view. Potential chiral magnetic solitons - hexagonal metal formates [NH4][M(HCOO)3] with M2+ = Mn, Fe, Co, and Ni and KCo(HCOO)3 containing dominating left-handed chiral antiferromagnetic helices that compete with interhelix interactions have been identified. The sign and strength of magnetic interactions not only between nearest neighbors, but also for longer-range neighbors in the metal formates have been calculated on the basis of structural data. Magnetic structures of these compounds are similar to that of the chiral magnetic soliton Cr1/3NbS2. The interrelation between chiral polarization of crystalline and magnetic structures in the metastable polymorph KCo(HCOO)3 has been demonstrated.

cond-mat.mtrl-sci↗
arXiv2014

Role of structural factors in formation of chiral magnetic soliton lattice in Cr1/3NbS2

The sign and strength of magnetic interactions not only between nearest neighbors, but also for longer-range neighbors in the Cr1/3NbS2 intercalation compound have been calculated on the basis of structural data. It has been found that left-handed spin helices in Cr1/3NbS2 are formed from strength-dominant at low temperatures AFM interactions between triangular planes of Cr3+ ions through the plane of just one of two crystallographically equivalent diagonals of side faces of embedded into each other trigonal prisms building up the crystal lattice of magnetic Cr3+ ions. These helices are oriented along the c axis and packed into two-dimensional triangular lattices in planes perpendicular to these helices directions and lay one upon each other with a displacement. The competition of the above AFM helices with weaker inter-helix AFM interactions could promote the emergence of a long-period helical spin structure. One can assume that in this case the role of Dzyaloshinskii-Moriya interaction cosists in final ordering and stabilization of chiral spin helices into a chiral magnetic soliton lattice. The possibility of emergence of solitons in M1/3NbX2 and M1/3TaX2 (M = d-elements; X = S and Se) intercalate compounds has been examined. Two important factors caused by the crystal structure (predominantnchiral magnetic helices and their competition with weaker inter-helix interactions not destructing the system quasi-one-dimensional character) can be used for the crystal chemistry search of solitons.

cond-mat.mtrl-sci↗
arXiv2013

Prediction of inorganic superconductors with quasi-one-dimensional crystal structure

Models of superconductors having a quasi-one-dimensional crystal structure based on the convoluted into a tube Ginzburg sandwich, which comprises a layered dielectric-metal-dielectric structure, have been suggested. The critical crystal chemistry parameters of the Ginzburg sandwich determining the possibility of the emergence of superconductivity and the Tc value in layered high-Tc cuprates, which could have the same functions in quasi-one-dimensional fragments (sandwich-type tubes), have been examined. The crystal structures of known low-temperature superconductors, in which one can mark out similar quasi-one- dimensional fragments, have been analyzed. Five compounds with quasi-one-dimensional structures, which can be considered as potential parents of new superconductor families, possibly with high transition temperatures, have been suggested. The methods of doping and modification of these compounds are provided.

cond-mat.supr-con↗
arXiv2011

Magnetoelectric ordering of BiFeO3 from the perspective of crystal chemistry

In this paper we examine the role of crystal chemistry factors in creating conditions for formation of magnetoelectric ordering in BiFeO3. It is generally accepted that the main reason of the ferroelectric distortion in BiFeO3 is concerned with a stereochemical activity of the Bi lone pair. However, the lone pair is stereochemically active in the paraelectric orthorhombic beta-phase as well. We demonstrate that a crucial role in emerging of phase transitions of the metal-insulator, paraelectric-ferroelectric and magnetic disorder-order types belongs to the change of the degree of the lone pair stereochemical activity - its consecutive increase with the temperature decrease. Using the structural data, we calculated the sign and strength of magnetic couplings in BiFeO3 in the range from 945 C down to 25 C and found the couplings, which undergo the antiferromagnetic-ferromagnetic transition with the temperature decrease and give rise to the antiferromagnetic ordering and its delay in regard to temperature, as compared to the ferroelectric ordering. We discuss the reasons of emerging of the spatially modulated spin structure and its suppression by doping with La3+.

cond-mat.mtrl-sci↗
arXiv2008

Crystal chemistry aspects of the magnetically induced ferroelectricity in TbMn2O5 and BiMn2O5

The origin of magnetic frustration was stated and the ions whose shift is accompanied by emerging magnetic ordering and ferroelectricity in TbMn2O5 and BiMn2O5 were determined on the basis of calculation of magnetic coupling parameters by using the structural data. The displacements accompanying the magnetic ordering are not polar, they just induce changes of bond valence (charge disordering) of Mn1 and Mn2, thus creating instability of the crystal structure. To approximate again the bond valence to the initial value (charge ordering) under magnetic ordering conditions is possible only due to polar displacement of Mn2 (or O1) and O4 ions along the b axis that is the cause of ferroelectric transition.

cond-mat.mtrl-sci↗