Magnetocaloric effect in an Ising–Heisenberg diamond chain with direct monomer spin couplings

Abstract

We study the magnetocaloric effect (MCE) in a spin’1/2 distorted Ising–Heisenberg diamond chain with direct monomer spin couplings. The ground state, isoentropy curves, and adiabatic cooling rate are examined within an exact analytical approach based on the transfer‐matrix technique. We find that the enhancing MCE in the vicinity of the critical field is very sensitive to the nature of field‐induced phase transitions. When the ground‐state phase transitions result from breaking up quantum entanglement states of Heisenberg spins, close to these critical fields, the signal associated with the cooling rate is very small and strongly suppressed by thermal fluctuations. By contrast, the one near the saturation field corresponding to the destruction of antiferromagnetic Ising spin order is considerably large and presents a complex temperature dependence. Interestingly, it can even be enhanced by temperature; this property reflects the intrinsic properties of the antiferromagnetic Ising spin chain and favors the use of frustrated antiferromagnets as promising working substances in low‐temperature magnetic refrigeration.

Exactly solved mixed spin-(1,1/2) Ising–Heisenberg diamond chain with a single-ion anisotropy

“…Owing to this fact, a lot of attention has been also paid to a rigorous treatment of various versions of the spin-1/2 Ising-Heisenberg diamond chain [15][16][17][18][19][20][21][22][23][24][25] and the Ising-Hubbard diamond chain [26][27][28][29].…”

Absence of actual plateaus in zero-temperature magnetization curves of quantum spin clusters and chains

“…The magnetization curves, thus, for the Ising-Heisenberg spin systems share almost all features with the magnetization curves of the small spin clusters, but can contain much more intermediate magnetization plateaus. Various variants of the Ising-Heisenberg chains have been examined: diamond-chain, [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] saw-tooth chain, 29,30 orthogonal-dimer chain, [31][32][33] tetrahedral chain, [34][35][36][37][38] and some special examples relevant to real magnetic materials. [39][40][41][42] In the present work, we will rigorously examine a magnetization process of a few quantum Heisenberg spin clusters and Ising-Heisenberg diamond chain, which will not display strict magnetization plateaus on assumption that some constituent spins have different Landé g-factors and may be a XY-anisotropy of the exchange interaction.…”

Non-conserved magnetization operator and ‘fire-and-ice’ ground states in the Ising-Heisenberg diamond chain

“…Due to its symmetric properties and relative simplicity the diamond chain is also the most popular one-dimensional structure for the theoretical research in the field of the Ising-Heisenberg spin lattices. Various physical effects and issues have been considered in the context of the corresponding model on the diamond chain or its modification, magnetization plateaus and zero-temperature phase diagrams, higher spin, mixed spins, four-spin interaction, magnetocaloric effect, entanglement and quantum state transfer, just to mention few of them [4,22,24,27,29,30,[32][33][34][35][36][37][38][39][40][41]50].…”