Heterobimetallic Dy-Cu coordination compound as a classical-quantum ferrimagnetic chain of regularly alternating Ising and Heisenberg spins

Abstract

A classical-quantum chain composed of regularly alternating Ising and Heisenberg spins is rigorously solved by considering two distinct local anisotropy axes of the Ising spins. The ground-state phase diagram and magnetization curves are examined depending on a spatial orientation of the applied magnetic field. The phase diagram totally consists of four distinct phases and a few macroscopically degenerate points, where an outstanding coexistence of perfect order and complete disorder occurs within the so-called 'half-fire, half-ice' state. The zero-temperature magnetization curves generally exhibit a smooth dependence on a magnetic field owing to a canting angle between two coplanar anisotropy axes of the Ising spins, which enforces a misalignment of the magnetization vector from a direction of the applied magnetic field. It is evidenced that the investigated spin-chain model reproduces magnetic features of the heterobimetallic coordination compound Dy(NO) 3 (DMSO) 2 Cu(opba)(DMSO) 2 (DMSO=dimethylsulfoxide, opba=orthophenylenebisoxamato). The high-field magnetization data reported for the powder sample of this polymeric coordination compound generally display a substantial smoothing on account of a powder averaging.

A conjecture on the relationship between critical residual entropy and finite temperature pseudo-transitions of one-dimensional models

“…An alternative way to obtain phase boundary residual entropy could be by using the combinatorial technique. Similar to that discussed in the reference [16,17] to find residual entropy.…”

Local distributions of the 1D dilute Ising model

“…To date, exact solutions have been found for various complex models based on the 1D Ising model. They includes Blume-Emery-Griffiths model [1][2][3] , the model with localized Ising-like spins and exchanging electrons 4 , the models with single-ion anisotropy for the spin-1 chain [5][6][7] or the mixed spin-1/2 and spin-1 Ising chain [8][9][10] , the Ising-Heisenberg "decorated" chains, ladders, and tubes [11][12][13][14][15][16][17][18][19][20] and the Ising-Hubbard diamond chain and ladder 21,22 . These systems show many subtle and important phenomena, including quantized plateaux in the magnetization curves, quantum entanglement, quasi-phases and pseudo-transitions 23 , and describe the properties of real materials, such as the polymeric coordination compounds (see Refs.…”

“…These systems show many subtle and important phenomena, including quantized plateaux in the magnetization curves, quantum entanglement, quasi-phases and pseudo-transitions 23 , and describe the properties of real materials, such as the polymeric coordination compounds (see Refs. in 10,12,[18][19][20]22 ). At the same time, the analysis of the conventional 1D Ising model also continues taking into account higher spin S values 24 , two kinds of spins 25 , the random short-and long-range interactions 26,27 , the next-nearest-neighbour coupling 28 and the magnetic field [29][30][31] .…”

Ground State, Magnetization Process and Bipartite Quantum Entanglement of a Spin-1/2 Ising-Heisenberg Model on Planar Lattices of Interconnected Trigonal Bipyramids

“…The investigations brought a deeper insight into the thermal and magnetic-field-driven changes of the phenomenon [36][37][38][39][40][41][42][43], the impact of the model's parameters on the phenomenon [36,[39][40][41][42][43][44][45], as well as the evolution of the phenomenon near and above second-order (continuous) phase transitions [44,45] without any artefacts arising from approximations. Despite their simplicity and the general opinion that the simpler mixed-spin Ising-Heisenberg systems involving isolated local quantum correlations are artificial models, some of the results were in a very good correspondence with ones obtained for more complex Heisenberg counterparts [40] and also with experiments [38,46,47].…”