Study of Integer Spin S = 1 in the Polar Magnet β-Ni(IO3)2

Abstract

Polar magnetic materials exhibiting appreciable asymmetric exchange interactions can potentially host new topological states of matter such as vortex-like spin textures; however, realizations have been mostly limited to half-integer spins due to rare numbers of integer spin systems with broken spatial inversion lattice symmetries. Here, we studied the structure and magnetic properties of the S = 1 integer spin polar magnet β-Ni(IO3)2 (Ni2+, d8, 3F). We synthesized single crystals and bulk polycrystalline samples of β-Ni(IO3)2 by combining low-temperature chemistry techniques and thermal analysis and characterized its crystal structure and physical properties. Single crystal X-ray and powder X-ray diffraction measurements demonstrated that β-Ni(IO3)2 crystallizes in the noncentrosymmetric polar monoclinic structure with space group P21. The combination of the macroscopic electric polarization driven by the coalignment of the (IO3)− trigonal pyramids along the b axis and the S = 1 state of the Ni2+ cation was chosen to investigate integer spin and lattice dynamics in magnetism. The effective magnetic moment of Ni2+ was extracted from magnetization measurements to be 3.2(1) µB, confirming the S = 1 integer spin state of Ni2+ with some orbital contribution. β-Ni(IO3)2 undergoes a magnetic ordering at T = 3 K at a low magnetic field, μ0H = 0.1 T; the phase transition, nevertheless, is suppressed at a higher field, μ0H = 3 T. An anomaly resembling a phase transition is observed at T ≈ 2.7 K in the Cp/T vs. T plot, which is the approximate temperature of the magnetic phase transition of the material, indicating that the transition is magnetically driven. This work offers a useful route for exploring integer spin noncentrosymmetric materials, broadening the phase space of polar magnet candidates, which can harbor new topological spin physics.

MIO3F (M = Co and Ni): Magnetic Iodate Fluorides with Zigzag Chains

“…Finally, a three-dimensional long-range antiferromagnetic order occurs at 16.5 K for 1 and 5.7 K for 2 . Such antiferromagnetic interactions commonly exist in other cobalt or nickel iodates. , In 2 , the large parameter of |θ|/ T N = 7.2 further confirms the low dimensionality and spin frustration. Meanwhile, due to the weaker intrachain interaction J 2 compared to intrachain interactions of J 1 or J 1 ′ as well as non-negligible interchain interactions of J 3 , J 4 , and J 5 , antiferromagnetic ground states are achieved both in zigzag spin chain systems of 1 and 2 .…”

“…However, iodates for magnetic properties have rarely been reported. − In particular, none of the magnetic iodate fluorides has been synthesized and reported yet till now. Here, we first report two new magnetic iodate fluorides MIO 3 F (M = Co 1 and Ni 2 ) by a hydrothermal method with interesting magnetic properties.…”

Ln2(SeO3)2(SO4)(H2O)2 (Ln=Sm, Dy, Yb): A Mixed‐Ligand Pathway to New Lanthanide(III) Multifunctional Materials Featuring Nonlinear Optical and Magnetic Anisotropy Properties

“…The relatively low effective moments observed in these samarium compounds are likely connected to the strong crystal field effect of the 6 H 5/2 multiplet. To understand how magnetization evolves as a function of magnetic field, we measured field‐dependent magnetization from μ 0 H =0 T–7 T at T =2 K (Figure 3b).The Brillouin function illustrates magnetization of an ideal paramagnet where the spin interaction is negligible [8b, 23] . The M ( H ) curve of the Sm compound only approaches ≈20 % of the saturation moment estimated by the Brillouin function, suggesting significant orbital contribution and high magnetic anisotropy [24] .…”

Single-Ion Behavior in New 2-D and 3-D Gadolinium 4f7 Materials: CsGd(SO4)2 and Cs[Gd(H2O)3(SO4)2]·H2O

“…To evaluate the spin state of the Gd 3+ cation in CsGd­(SO 4 ) 2 and Cs­[Gd­(H 2 O) 3 (SO 4 ) 2 ]·H 2 O and determine the magnetic properties of the materials, we performed temperature-dependent magnetization at μ 0 H = 9 T and field-dependent magnetization at T = 2 K (Figure ). The magnetic susceptibility data of these materials follow the Curie–Weiss law over a wide temperature range of 30 K ≤ T ≤ 300 K (eq ): where C is the Curie constant, θ CW is the Curie–Weiss temperature, and χ 0 is the temperature-independent contribution to the susceptibility, which includes the small diamagnetic signals of the electron core and the sample holder . The effective magnetic moment μ eff per Gd 3+ cation was estimated using eq : where N A is the Avogadro number and k B is the Boltzmann constant.…”

“…where C is the Curie constant, θ CW is the Curie−Weiss temperature, and χ 0 is the temperature-independent contribution to the susceptibility, which includes the small diamagnetic signals of the electron core and the sample holder. 36 The effective magnetic moment μ eff per Gd 3+ cation was estimated using eq 2: i k j j j j j j y…”