Theory of High-Temperature Susceptibility of Heisenberg Ferromagnets Having Nearest-Neighbor Bilinear and Biquadratic Exchange Interactions

1965 ◽  
Vol 138 (5A) ◽  
pp. A1441-A1444 ◽  
Author(s):  
R. I. Joseph
Keyword(s):  
High Temperature ◽  
Nearest Neighbor ◽  
Exchange Interactions ◽  
Biquadratic Exchange ◽  
Temperature Susceptibility

MAGNETIC BEHAVIOR OF IRON IONS IN THE P2O5·CaO GLASS MATRIX

2003 ◽  
Vol 17 (24) ◽  
pp. 1271-1275 ◽  
Author(s):  
I. ARDELEAN ◽  
C. ANDRONACHE ◽  
P. PǍŞCUŢǍ
Keyword(s):  
Magnetic Susceptibility ◽  
High Temperature ◽  
Magnetic Moment ◽  
Glass Matrix ◽  
Magnetic Behavior ◽  
Iron Ions ◽  
Ion Content ◽  
Dipole Interactions ◽  
Valence States ◽  
Temperature Susceptibility

The temperature dependence of the magnetic susceptibility of x Fe 2 O 3·(100-x)-[ P 2 O 5· CaO ] glasses with 0<x≤50 mol % have been investigated. These data revealed that the valence states and the distribution of iron ions in the glass matrix depend on the Fe 2 O 3 content. For the glasses with x≤1 mol % only Fe 3+ ions are evidenced. In the case of the glasses with 3≤x≤35 mol % both Fe 3+ and Fe 2 ions co-exist in the P 2 O 5· CaO glass matrix, the Fe 2+ ion content is higher than that of the Fe 3+ ions for glasses with x≥10 mol %. For the glasses with x>35 mol %, the evaluated values of the μ eff indicate either the presence of Fe + ions or the coordination influence on the magnetic moment of iron ions, but the presence of small quantities of the antiferromagnetic or ferrimagnetic interactions between iron ions in studied temperature range cannot be excluded. The high temperature susceptibility results indicate that the iron ions are isolated or participate in dipole-dipole interactions for glasses with x≤35 mol % and are antiferromagnetically coupled for higher contents of Fe 2 O 3.

THE GROUND-STATE PHASE DIAGRAMS OF THE SPIN-2 ISING MODEL

2007 ◽  
Vol 21 (31) ◽  
pp. 5265-5274 ◽  
Author(s):  
AHMET ERDİNÇ
Keyword(s):  
Magnetic Field ◽  
Ising Model ◽  
External Magnetic Field ◽  
Phase Diagrams ◽  
Crystal Field ◽  
Ground State ◽  
Exchange Interactions ◽  
Nearest Neighbors ◽  
Biquadratic Exchange ◽  
Model Hamiltonian

The ground-state phase diagrams are obtained for the spin-2 Ising model Hamiltonian with bilinear and biquadratic exchange interactions and a single-ion crystal field. The interactions are assumed to be only between nearest-neighbors. Obtained phase diagrams are presented in the (Δ,J), (K,J), (Δ/J,K/J), (Δ/|J|,K/|J|), (Δ/|K|,J/|K|), (H/J,Δ/J), (H/|J|,Δ/|J|), (H/J,K/J), and (H/|J|,K/|J|) planes where J, K, Δ, and H are the bilinear, biquadratic exchange interactions, the single-ion crystal field, and the external magnetic field, respectively. The influence of the external magnetic field on the spin configurations is investigated.

scholarly journals Обменные взаимодействия в паре ионов Cr-=SUP=-3+-=/SUP=--Cr-=SUP=-3+-=/SUP=- в диамагнитной матрице ABO-=SUB=-3-=/SUB=- (A=Ga, In, Sc)

2020 ◽  
Vol 62 (3) ◽  
pp. 403
Author(s):  
А.М. Воротынов ◽  
В.В. Руденко ◽  
О.В. Воротынова
Keyword(s):  
Magnetic Resonance ◽  
Ion Pairs ◽  
Exchange Interactions ◽  
Resonance Technique ◽  
Biquadratic Exchange ◽  
Magnetic Resonance Technique

Abstract The exchange interactions in the Cr^3+–Cr^3+ ion pairs in the isostructural ABO_3 (A = Ga, In, Sc) diamagnetic compounds have been examined using the magnetic resonance technique. The values of bilinear and biquadratic exchange interactions have been determined. It is shown that the biquadratic exchange in the Cr^3+–Cr^3+ pair in these compounds is caused by the exchange striction.

Loss of classicality in the alternating spin-½/spin-1 chain, in the presence of next-neighbor couplings and Dzyaloshinskii-Moriya interactions

2022 ◽  
Author(s):  
Abhiroop Lahiri ◽  
Swapan K Pati
Keyword(s):  
Ground State ◽  
Nearest Neighbor ◽  
Spiral Structure ◽  
Exchange Interactions ◽  
Quantum Fluctuations ◽  
Wave Theory ◽  
Range Order ◽  
Density Matrix Renormalization Group ◽  
Density Matrix Renormalization ◽  
Spin Spiral

Abstract We have considered and alternating spin-½/spin-1 chain with nearest-neighbor (J1), next-nearest neighbor (J2) antiferromagnetic Heisenberg interactions along with z-component of the Dzyaloshinskii-Moriya(DM) (Dz) interaction. The Hamiltonian has been studied using (a) Linear Spin-Wave Theory(LSWT) and (b) Density Matrix Renormalization Group (DMRG). The system had been reported earlier as a classical ferrimagnet only when nearest neighbor exchange interactions are present. Both the antiferromagnetic next-nearest neighbor interactions and DM interactions introduce strong quantum fluctuations and due to which all the signatures of ferrimagnetism vanishes. We find that the nonzero J2 introduces strong quantum fluctuations in each of the spin sites due to which the z-components of both spin-1 and spin-1/2 sites average out to be zero. The ground state becomes a singlet. The presence of J1 along with Dzintroduces a short range order but develops long range order along the XY plane. J1 along with J2induces competing phases with structure factor showing sharp and wide peaks, at two different angles reflecting the spin spiral structure locally as well as in the underlying lattice. Interestingly, we find that the Dz term removes the local spin spiral structure in z-direction, while developing a spiral order in the XY plane.

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