The TeVO4 compound is a model system of a frustrated spin chain with a rich phase diagram. The main result is a discovery of a magnetic stripe structure on the nano-scale, which appears at the transition between the spiral and collinear magnetic orders. In contrast to known strongly-correlated electron systems, here stripes are stabilized in the absence of long-range magnetic interactions and are likely driven by weak frustrated interchain interactions. The presented model system allows better understanding of the origin of the analogous nanometer-sized modulation in other systems, e.g., high-temperature superconductors.
COBISS.SI-ID: 28648487
We have investigated orientational ordering of thermomechanically active liquid crystalline elastomer microparticles, dispersed in PDMS elastomer, using quadrupole-perturbed deuteron NMR. We have also developed a theoretical model of the behavior of orientational order parameter in the external magnetic field as a function of the microdomain nematic order parameter and diamagnetic anisotropy, the viscosity of the uncured matrix resin, and of the curing process kinetic factor. By comparing theoretical predictions with experimentally determined values of, we have demonstrated that the degree of orientational ordering and, consequently, the effective thermomechanical response of the composite material, can be tailored by controlling the external magnetic field as well as by properly adjusting the curing time.
COBISS.SI-ID: 29955111
In the CsO2 quantum antiferromagnet the interplay of spin degrees of freedom with lattice vibrations and orbital ordering leads to complex and interesting physics. Using magnetic resonance techniques, we showed that the system exhibits an exotic Tomonaga-Luttinger-liquid state at low temperatures, where orbital ordering takes place. Sizeable lattice vibrations at higher temperatures lead to a huge temperature dependence of the exchange interaction, providing the first clear demonstration of this effect predicted three decades ago.
COBISS.SI-ID: 28759079
A study of mixed ferro/antiferromagnetic phase in Cu3Bi(SeO3)2O2Br system has revealed the ability of metamagnetic materials to absorb electromagnetic radiation in an extremely broad frequency range. The effect is controlled by the external magnetic field, which actuates a mixed ferro/antiferromagnetic phase, where the absorption in Cu3Bi(SeO3)2O2Br system extends over at least nine orders of frequency scale. Considering that artificial metamagnets (magnetic multilayers) allow for a direct control over the required magnetic field, a novel way of tuning the materials' functional properties is imminent.
COBISS.SI-ID: 28566311
We have investigated gas sensors based on WO3 nanoneedles (NN) decorated with PdO nanoparticles (NP). Morphological, structural, and elemental composition analysis has revealed that the Pd(acac)2 precursor was very suitable to decorate WO3 NNs with uniform and well-dispersed PdO NPs. Gas-sensing results revealed that decoration with PdO NPs led to an ultrasensitive and selective hydrogen (H2) gas sensor with low operating temperature (150 °C). The response of decorated NNs is 755-times higher than that of bare WO3 NNs. Humidity measurements showed that PdO/WO3 sensors displayed low-cross-sensitivity toward water vapor, compared to bare WO3 sensors.
COBISS.SI-ID: 29449511