Two-dimensional solitons in spin nematic states for magnets with an isotropic exchange interaction

2015 ◽  
Vol 41 (5) ◽  
pp. 382-389 ◽  
Author(s):  
E. G. Galkina ◽  
B. A. Ivanov ◽  
O. A. Kosmachev ◽  
Yu. A. Fridman
Keyword(s):  
Exchange Interaction ◽  
Two Dimensional ◽  
Isotropic Exchange

Electronic properties of quasi two-dimensional transition metals chalcogenides with low-dimensional magnetism

Doklady BGUIR ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 87-95
Author(s):  
M. S. Baranava ◽  
P. A. Praskurava
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Exchange Interaction ◽  
Electronic Properties ◽  
Metal Atom ◽  
Transition Metal Atom ◽  
Two Dimensional ◽  
Transition Metal Atoms ◽  
Ground Magnetic ◽  
Low Dimensional

The search for fundamental physical laws which lead to stable high-temperature ferromagnetism is an urgent task. In addition to the already synthesized two-dimensional materials, there remains a wide list of possible structures, the stability of which is predicted theoretically. The article suggests the results of studying the electronic properties of MAX3 (M = Cr, Fe, A = Ge, Si, X = S, Se, Te) transition metals based compounds with nanostructured magnetism. The research was carried out using quantum mechanical simulation in specialized VASP software and calculations within the Heisenberg model. The ground magnetic states of twodimensional MAX3 and the corresponding energy band structures are determined. We found that among the systems under study, CrGeTe3 is a semiconductor nanosized ferromagnet. In addition, one is a semiconductor with a bandgap of 0.35 eV. Other materials are antiferromagnetic. The magnetic moment in MAX3 is localized on the transition metal atoms: in particular, the main one on the d-orbital of the transition metal atom (and only a small part on the p-orbital of the chalcogen). For CrGeTe3, the exchange interaction integral is calculated. The mechanisms of the formation of magnetic order was established. According to the obtained exchange interaction integrals, a strong ferromagnetic order is formed in the semiconductor plane. The distribution of the projection density of electronic states indicates hybridization between the d-orbital of the transition metal atom and the p-orbital of the chalcogen. The study revealed that the exchange interaction by the mechanism of superexchange is more probabilistic.

MECHANISM OF STRIPES IN t–J MODEL

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3662-3667
Author(s):  
TÔRU SAKAI
Keyword(s):  
Phase Separation ◽  
Exchange Interaction ◽  
Correlation Functions ◽  
Nearest Neighbor ◽  
Two Dimensional ◽  
Model Based ◽  
Stripe Order ◽  
Charge Stripe

We consider a possible mechanism of the charge stripe order due to the next-nearest neighbor exchange interaction J′ in the two-dimensional t–J model, based on the concept of the phase separation. We also calculate some hole correlation functions of the finite cluster of the model using the numerical diagonalization, to examine the realization of the mechanism.

Exchange interaction as studied by EPR in a two-dimensional molecular composite [NH3(CH2)4NH3]MnCl4

1998 ◽  
Vol 106 (6) ◽  
pp. 385-389 ◽  
Author(s):  
Jean-Claude Bissey ◽  
Nathalie Filloleau ◽  
Nguyen-Ba Chanh ◽  
René Berger ◽  
Serge Flandrois
Keyword(s):  
Exchange Interaction ◽  
Two Dimensional

Synthesis and Characterization of the Heptanuclear [MnIII 6 CoIII]3+ Triplesalen Complex: Evidence for Exchange Pathways Involving Low-spin CoIII

2010 ◽  
Vol 65 (3) ◽  
pp. 295-303 ◽  
Author(s):  
Erich Krickemeyer ◽  
Veronika Hoeke ◽  
Anja Stammler ◽  
Jürgen Schnack ◽  
Hartmut Bögge ◽  
...  
Keyword(s):  
Exchange Interaction ◽  
Metal Ion ◽  
Magnetic Measurements ◽  
Variable Temperature ◽  
Molecular Structures ◽  
Magnetic Data ◽  
Zero Field ◽  
Central Metal ◽  
Zero Field Splitting ◽  
Isotropic Exchange

The reaction of the tert-butyl-substituted triplesalen ligand H6talent-Bu2 with MnII(OAc)2・ 4H2O and K3[CoIII(CN)6] results in the formation of the heptanuclear complex [{(talent-Bu2 )- (MnIII(MeOH))3}2{CoIII(CN)6}](PF6)2(OAc)・11MeOH ([MnIII6 CoIII](PF6)2(OAc)・11MeOH, 1 ・11MeOH), which has been characterized by FT-IR spectroscopy, elemental analysis, ESI-MS, single-crystal X-ray diffraction, and magnetic measurements. The molecular structure of the [MnIII6 CoIII]3+ complex is closely related to the already published analogs [MnIII6CrIII]3+ and [MnIII6 FeIII]3+. Variable-temperature variable-field and μeff vs. T magnetic data have been analyzed in detail by full-matrix diagonalization of the appropriate spin-Hamiltonian consisting of isotropic exchange, zero-field splitting, and Zeeman interaction, taking into account the relative orientation of the D tensors. This allowed a careful inspection of the MnIII-MnIII exchange interaction involving a diamagnetic central metal ion. A satisfactory reproduction of the magnetic data required the incorporation not only of an exchange interaction between the MnIII ions belonging to one triplesalen half unit, but also of an exchange coupling between MnIII ions belonging to different triplesalen subunits. Satisfactory reproduction of the experimental data has been obtained for the parameter set J1 = −(0.50±0.04) cm−1, J2 = +(0.05±0.02) cm−1, and D = −(2.5±0.5) cm−1. A detailed analysis of the J1 coupling taking into account the molecular structures of the three available heptanuclear complexes [MnIII6MIII]3+ (M = Cr, Fe, Co) indicates that the exchange interaction between the MnIII ions belonging to the same triplesalen subunit involves not only an exchange pathway through the central phloroglucinol unit but also an exchange pathway through the central metal ion.

A possible mechanism for quasi-two-dimensional ferromagnetism: the spectrum gap induced by s - d exchange interaction

1996 ◽  
Vol 8 (23) ◽  
pp. 4157-4163
Author(s):  
Ping-Bo Zhao ◽  
Xiang-Dong Zhang ◽  
Bo-Zang Li ◽  
Fu-Cho Pu
Keyword(s):  
Exchange Interaction ◽  
Two Dimensional
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