Observation of a neutron spin resonance in the bilayered superconductor CsCa2Fe4As4F2
(2020)
Robustness of superconducting properties to transition metal substitution and impurity phases in Fe1-xVxSe
(2020)
Magnetic order and disorder in a quasi-two-dimensional quantum Heisenberg antiferromagnet with randomized exchange
(2020)
Enhancing easy-plane anisotropy in bespoke Ni(II) quantum magnets
Polyhedron 180 (2020)
Abstract:
漏 2020 The Authors We examine the crystal structures and magnetic properties of several S = 1 Ni(II) coordination compounds, molecules and polymers, that include the bridging ligands HF2鈭, AF62鈭 (A = Ti, Zr) and pyrazine or non-bridging ligands F鈭, SiF62鈭, glycine, H2O, 1-vinylimidazole, 4-methylpyrazole and 3-hydroxypyridine. Pseudo-octahedral NiN4F2, NiN4O2 or NiN4OF cores consist of equatorial Ni-N bonds that are equal to or slightly longer than the axial Ni-Lax bonds. By design, the zero-field splitting (D) is large in these systems and, in the presence of substantial exchange interactions (J), can be difficult to discriminate from magnetometry measurements on powder samples. Thus, we relied on pulsed-field magnetization in those cases and employed electron-spin resonance (ESR) to confirm D when J 鈮 D. The anisotropy of each compound was found to be easy-plane (D > 0) and range from 鈮 8鈥25 K. This work reveals a linear correlation between the ratio d(Ni-Lax)/d(Ni-Neq) and D although the ligand spectrochemical properties may play an important role. We assert that this relationship allows us to predict the type of magnetocrystalline anisotropy in tailored Ni(II) quantum magnets.Magnetism and N\'{e}el skyrmion dynamics in GaV$_{4}$S$_{8-y}$Se$_{y}$
(2020)