We reported on our nuclear magnetic resonance experiments in Cs3C60 and first demonstrated that its ambient pressure ground state is insulating with an antiferromagnetic order below 46 K. This insulating state has all characteristics of Mott insulators and thus clearly reflects the importance of electronic correlations in fullerides. Applying high hydrostatic pressures (exceeding 3.6 kbar) Cs3C60 becomes a metal and undergoes to a superconducting state at low temperatures. Critical temperature first increases with increasing pressure, but then reaches a broad maximum at TC = 38 K at 8 kbar.
COBISS.SI-ID: 22509351
With the help of nuclear magnetic resonance experiments we demonstrated that both known Cs3C60 polymorphs have insulating ground state under ambient pressure conditions. We showed that both critical temperatures follow universal parameter, that depends on the electron correlation energy.
COBISS.SI-ID: 23639591
This Chemical Society Reviews paper was prepared following the invitation by the CSR Editors. This review paper summarized current state of the art in the field of physical properties of icosahedral and decagonal quasicrystals (electrical resistivity, thermoelectric power, Hall coefficient and thermal conductivity), giving a survey of the experimental results and theoretical models. Large part of the paper is based on the results obtained in the Author's laboratory at the J. Stefan Institute.
COBISS.SI-ID: 26118439
Near-edge X-ray absorption spectroscopy (NEXAFS) is an essential analytical tool in material science. Combining NEXAFS with scanning transmission X-ray microscopy (STXM) adds spatial resolution and the possibility to study individual nanostructures. In this work, we described a full-field transmission X-ray microscope (TXM) that generates high resolution, large-area NEXAFS data with a collection rate two orders of magnitude faster than is possible with STXM. The TXM optical design combines a spectral resolution of E/DE5 13104 with a spatial resolution of 25 nm in a field of view of 15–20 mm and a data acquisition time of ∼1 s. As an example, we present image stacks and polarization-dependent NEXAFS spectra from individual anisotropic sodium and protonated titanate nanoribbons ((Na,H)TiNRs, HTiNRs)). Combined NEXAFS-TXM technique has the advantage that one image stack visualizes a large number of nanostructures and therefore already contains statistical information. This new high-resolution NEXAFS-TXM technique opens the way to advanced nanoscale science studies.
COBISS.SI-ID: 25317671
In the paper A. Zorko et al., Nat. Commun. 5, 3222 (2014), the authors reported the discovery of a paradigmatic magnetostructurally inhomogenous ground state of the geometrically frustrated α-NaMnO2 that stems from the system’s aspiration to remove magnetic degeneracy and is possible only due to existence of near-degenerate crystal structures. Using different experimental techniques they showed that the spin configuration of a monoclinic phase is disrupted by magnetically short-range-ordered nanoscale triclinic regions. Such phase separation has never been observed before solely in the magnetostructural channel, though it is reminiscent of charge-driven phase inhomogeneities of some chemically homogenous electronic systems, such as high-Tc cuprates and colossal-magnetoresistent manganites.
COBISS.SI-ID: 27449895