Related papers: Magnetic field enhanced structural instability in …
The effect of the external field on the weakly-discontinuous first-order phase transition is analyzed in the frame of the Landau theory. The transformation of the free energy expansion as a power series in the order parameter is suggested…
The interaction of light in terahertz frequency region with electromagnons in a sinusoidal incommensurate magnetic state in TbMnO3 is studied. A significant change in the frequency dependence of the dielectric constant e_zz near the…
In divalent Eu systems, the 4f local moment has a pure spin state J=S=7/2. Although the absence of orbital moment precludes crystal electric field effects, we report a sizeable magnetic anisotropy in single crystals of EuRh2Si2. We observed…
Magnetic and crystallographic transitions in the Cairo pentagonal magnet Bi2Fe4O9 are investigated by means of infrared synchrotron-based spectroscopy as a function of temperature (20 - 300 K) and pressure (0 - 15.5 GPa). One of the phonon…
We report a first-order phase transition at T_M=357 K in single crystal Ca_2RuO_4, an isomorph to the superconductor Sr_2RuO_4. The discontinuous decrease in electrical resistivity signals the near destruction of the Mott insulating phase…
We have studied the impact of the magnetic field on the electromagnon excitations in TbMnO3 crystal. Applying magnetic field along the c axis, we show that the electromagnons transform into pure antiferromagnetic modes, losing their polar…
In a previous work a model was proposed for the phase transitions of crystals with localized magnetic moments which at low temperature have a "conical" arrangement that at higher T transforms into a more symmetrical structure (depending on…
We report temperature dependent measurements of ambient pressure specific heat, magnetic susceptibility, anisotropic resistivity and thermal expansion as well as in-plane resistivity under pressure up to 20.8 kbar on single crystals of…
We present a comprehensive study of the temperature- and magnetic-field-dependent magnetization, specific heat, and local crystal structure across the first-order ferromagnetic-paramagnetic transition in Eu$_2$In. Anomalies in the…
Dielectric and magnetic properties of Eu0.5Ba0.25Sr0.25TiO3 are investigated between 10 K and 300 K in the frequency range from 10 Hz to 100 THz. A peak in permittivity revealed near 130 K and observed ferroelectric hysteresis loops prove…
We report a comprehensive experimental investigation of the magnetic structure of the cycloidal phase in Ca$_3$Ru$_2$O$_7$, which mediates the spin reorientation transition, and establishes its magnetic phase diagram. In zero applied field,…
We report an isothermal electric field-induced first-order phase transition from Mott-insulator to the metallic state in the epitaxial thin film of V$_2$O$_3$ in the temperature regime below its Mott transition temperature $\approx$ 180 K.…
The effect of an external (electro)magnetic field on the finite temperature transition of QCD is studied. We generate configurations at various values of the quantized magnetic flux with $N_f=2+1$ flavors of stout smeared staggered quarks,…
Our first-principles computations show that the ground state of PbTiO$_3$ under hydrostatic pressure transforms discontinuously from $P4mm$ to $R3c$ at 9 GPa. Spontaneous polarization decreases with increasing pressure so that the $R3c$…
Insulating helimagnetic Cu2OSeO3 shows sizeable magnetoelectric effects in its skyrmion phase. Using magnetization measurements, magneto-current analysis and dielectric spectroscopy, we provide a thorough investigation of magnetoelectric…
CuSiO_3, isotypic to the spin - Peierls compound CuGeO_3, was discovered recently as a metastable decomposition product of the silicate mineral dioptase, Cu_6Si_6O_{18}\cdot6H_2O. We investigated the physical properties of CuSiO_3 using…
The formation of excitonic insulator phases in quantum materials is often masked by structural distortions caused by the coupling between electronic and phononic order parameters. Here we show that the candidate material Ta$_2$NiSe$_5$ is…
The thermodynamic and electronic-transport properties of trigonal EuMg2Bi2 in ab-plane magnetic fields Hx and the A-type antiferromagnetic structure have recently been reported. At a temperature of 1.8 K < TN, the Eu magnetic moments with…
We consider theoretically the paramagnetic phases of EuTiO3 that represent configurations created by two sets of microscopic degrees of freedom (m-DOF): positional symmetry breaking due to octahedral rotations and magnetic symmetry breaking…
We report on the linear optical properties of the chiral magnet Cu2OSeO3, specifically associated with the absence of inversion symmetry, the chiral crystallographic structure, and magnetic order. Through spectroscopic ellipsometry, we…