Crystals of Li[N(CN)2] were synthesized from a metathesis reaction of stoichiometric amounts of aqueous solutions of Na[N(CN)2] and Li2[SO4] followed by subsequent treatment with ethanol and evaporation of the filtered‐off solution at 80 °C under normal atmospheric conditions. The single crystals of the title compound are transparent, colorless, and extremly hygroscopic. X‐ray structure analysis showed that Li[N(CN)2] crystallizes in the monoclinic space group P2/c with the cell parameters a = 530.79(8) pm, b = 524.89(9) pm, c = 1149.77(17) pm, β = 101.551(7)°, and Z = 4. The crystal structure contains Li+ cations in both tetrahedral and octahedral nitrogen coordination of the boomerang‐shaped [N≡C–N–C≡N]– anions. The vibrational spectra of Li[N(CN)2] are reported as well, together with ab initio calculations for geometry and harmonic frequencies of the free dicyanamide anion.

The small gap semiconductor α-RuCl has emerged as a promising candidate for quantum spin liquid materials. Thus far, Raman spectroscopy, neutron scattering, and magnetization measurements have provided valuable hints for collective spin behavior in α-RuCl bulk crystals. However, the goal of implementing α-RuCl into spintronic devices would strongly benefit from the possibility of electrically probing these phenomena. To address this, we first investigated nanoflakes of α-RuCl by Raman spectroscopy and observed similar behavior as in the case of the bulk material, including the signatures of possible fractionalized excitations. In complementary experiments, we investigated the electrical charge transport properties of individual α-RuCl nanoflakes in the temperature range between 120 and 290 K. The observed temperature-dependent electrical resistivity is consistent with variable range hopping behavior and exhibits a transition at about 180 K, close to the onset temperature observed in our Raman measurements. In conjunction with the established relation between structure and magnetism in the bulk, we interpret this transition to coincide with the emergence of fractionalized excitations due to the Kitaev interactions in the nanoflakes. Compared to the bulk samples, the transition temperature of the underlying structural change is larger in the nanoflakes. This difference is tentatively attributed to the dimensionality of the nanoflakes as well as the formation of stacking faults during mechanical exfoliation. The demonstrated devices open up novel perspectives toward manipulating the Kitaev-phase in α-RuCl via electrical means.

The magnetic and lattice properties of the S=1/2 quantum-spin-chain ferromagnet, CuAs2O4, mineral name trippkeite, were investigated. The crystal structure of CuAs2O4 is characterized by the presence of corrugated CuO2 ribbon chains. Measurements of the magnetic susceptibility, heat capacity, electron paramagnetic resonance and Raman spectroscopy were performed. Our experiments conclusively show that a ferromagnetic transition occurs at ∼7.4 K. Ab initio DFT calculations reveal dominant ferromagnetic nearest-neighbor and weaker antiferromagnetic nextnearest-neighbor spin exchange interactions along the ribbon chains. The ratio of Jnn/Jnnn is near -4, placing CuAs2O4 in close proximity to a quantum critical point in the Jnn -Jnnn phase diagram. TMRG simulations used to analyze the magnetic susceptibility confirm this ratio. Single-crystal magnetization measurements indicate that a magnetic anisotropy forces the Cu 2+ spins to lie in an easy plane perpendicular to the c-axis. An analysis of the field and temperature dependent magnetization by modified Arrott plots reveals a 3d-XY critical behavior. Lattice perturbations induced by quasi-hydrostatic pressure and temperature were mapped via magnetization and Raman spectroscopy.

We carried out detailed studies of the magnetic structure, magnetoelastic coupling, and thermal properties of EuCrO3 nano-powders from room temperature to liquid helium temperature. Our neutron powder diffraction and X-ray powder diffraction measurements provide precise atomic positions of all atoms in the cell, especially for the light oxygen atoms. The low-temperature neutron powder diffraction data revealed extra Bragg peaks of magnetic origin which can be attributed to a Gx antiferromagnetic structure with an ordered moment of ∼ 2.4 µB consistent with the 3d 3 electronic configuration of the Cr 3+ cations. Apart from previously reported antiferromagnetic and ferromagnetic transitions in EuCrO3 at low temperatures, we also observed an anomaly at about 100 K. This anomaly was observed in temperature dependence of sample's, lattice parameters, thermal expansion, Raman spectroscopy, permittivity and conductance measurements. This anomaly is attributed to the magnetoelastic distortion in the EuCrO3 crystal.

Atomically thin films of WSe2 from one monolayer up to 8 layers were deposited on an Al2O3 r-cut (11¯02) substrate using a hybrid-Pulsed Laser Deposition (PLD) system where a laser ablation of pure W is combined with a flux of Se. Specular X-ray reflectivities of films were analysed and were consistent with the expected thickness. Raman measurement and atomic force microscopy confirmed the formation of a WSe2 monolayer and its spatial homogeneity over the substrate. Grazing-incidence X-ray diffraction uncovered an in-plane texture in which WSe2 [101¯0] preferentially aligned with Al2O3 [112¯0]. These results present a potential to create 2D transition metal dichalcogenides by PLD, where the growth kinetics can be steered in contrast to common growth techniques like chemical vapor deposition and molecular beam epitaxy.