Ferrimagnetic Behaviors of Mixed Spin Ising Nanotube with Crystal Field

AbstractWe use exact recursion relations to study the magnetic properties of the half-integer mixed spin-5/2 and spin-3/2 Blume-Capel Ising ferromagnetic system on the two-fold Cayley tree that consists of two sublattices A and B. Two positive crystal-field interactions Δ1 and Δ2 are considered for the sublattice with spin-5/2 and spin-3/2 respectively. For different coordination numbers q of the Cayley tree sites, the phase diagrams of the model are presented with a special emphasis on the case q = 3, since other values of q reproduce similar results. First, the T = 0 phase diagram is illustrated in the (D A = Δ1/J,D B = Δ2/J) plane of reduced crystal-field interactions. This diagram shows triple points and coexistence lines between thermodynamically stable phases. Secondly, the thermal variation of the magnetization belonging to each sublattice for some coordination numbers q are investigated as well as the Helmoltz free energy of the system. First-order and second-order phase transitions are found. The second-order phase transitions become sharper and sharper when D A or D B increases. The first-order transitions only exist for some appropriate non-zero values of D A and/or D B. The corresponding transition lines never connect to the second-order transition lines. Thus, the non-existence of tricritical points remains one of the key features of the present model. The magnetic exponent β 0 of the model is estimated and found to be ¼ at small values of D A = D B = D and β 0 = ½ at large values of D. At intermediate values of D, there is a crossover region where the magnetic exponent displays interesting behaviours.

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The diluted mixed-spin transverse Ising system with longitudinal crystal field interactions

Journal of Magnetism and Magnetic Materials ◽

10.1016/s0304-8853(00)00568-0 ◽

2000 ◽

Vol 222 (3) ◽

pp. 355-367 ◽

Cited By ~ 11

Author(s):

N. Benayad ◽

A. Fathi ◽

R. Zerhouni

Keyword(s):

Crystal Field ◽

Ising System ◽

Mixed Spin

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Mixed spin-3/2 and spin-2 nanowire: magnetic properties and hysteresis behaviors

Multidiscipline Modeling in Materials and Structures ◽

10.1108/mmms-09-2020-0233 ◽

2021 ◽

Vol 17 (3) ◽

pp. 615-629

Author(s):

Karima El Kihel ◽

Rachid Aharrouch ◽

Yahya Al Qahoom ◽

Mohamed Madani ◽

Nabil Hachem ◽

...

Keyword(s):

Magnetic Properties ◽

Exchange Interaction ◽

Crystal Field ◽

Hysteresis Loops ◽

Magnetic Nanowires ◽

Content Type ◽

Mixed Spins ◽

Mixed Spin ◽

Compensation Behavior ◽

Hamiltonian Parameters

PurposeThe purpose of this article is to investigate the magnetic properties and the hysteresis loops behavior of a ferrimagnetic cubic nanowire with mixed spins SA = 3/2 and SB = 2.Design/methodology/approachWe have used the Monte Carlo simulation to examine the influences of the exchange interaction JB, the crystal field ∆ and the temperature on the magnetic properties and hysteresis loops of the nanowire. More exactly, we have shown the temperature dependence of the sublattice magnetizations (mA and mB) and the total magnetization (M) for several values of the Hamiltonian parameters, as well as the corresponding phase diagrams. Finally, the effect of an external magnetic field is studied by plotting the hysteresis loops of the system for different values of exchange interaction, crystal field and temperature.FindingsThe obtained results show the existence of second-order phase transitions, as well as the compensation behavior. Moreover, according to the values of the Hamiltonian parameters, the system can exhibit one, two or three hysteresis loops.Originality/valueThe magnetic nanowires are of great interest in experimental works, but without theoretical explanations, the experimental results cannot be clarified in depth. For this, we contribute through this theoretical study to understand the nanowires, especially those with mixed spins (2, 3/2).

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