Related papers: Thermal expansion of the superconducting ferromagn…
We report thermal expansion measurements on a single crystal of the superconducting ferromagnet UCoGe for magnetic fields applied along the main orthorhombic axes. The thermal expansion cell was mounted on a piezo-electric rotator in order…
We review our recent results on ferromagnetic superconductors, URhGe and UCoGe. High quality single crystals of both compounds were successfully grown. The specific heat shows a clear jump related to the superconducting transition in UCoGe.…
UCoGe exhibits superconductivity in the presence of ferromagnetism. When a field is applied along the b axis (perpendicular to the easy axis), ferromagnetism is weakened and superconductivity is enhanced. This enhancement has been…
We performed thermal conductivity measurements on a single crystal of the ferromagnetic superconductorUCoGe under magnetic field. Two different temperature dependencies of the thermal conductivity are observed, for H//b linear at low…
Magnetoresistivity measurements with fine tuning of the field direction on high quality single crystals of the ferromagnetic superconductor UCoGe show anomalous anisotropy of the upper critical field H_c2. H_c2 for H // b-axis (H_c2^b) in…
We report upper critical field $B_{c2}(T)$ measurements on a single-crystalline sample of the ferromagnetic superconductor UCoGe. $B_{c2}(0)$ obtained for fields applied along the orthorhombic axes exceeds the Pauli limit for $B \parallel…
High-resolution thermal-expansion and specific-heat measurements were performed on single crystalline BaFe2(As1-xPx)2 (0 < x < 0.33, x = 1). The observation of clear anomalies allows to establish the thermodynamic phase diagram which…
Thermal conductivity measurements in the superconducting state of the ferromagnet UCoGe were performed at very low temperatures and under magnetic field on samples of different qualities and with the heat current along the three…
We report a magnetoresistance study of the superconducting ferromagnet UCoGe. The data, taken on single-crystalline samples, show a pronounced structure at $B^* = 8.5$~T for a field applied along the ordered moment $m_0$. Angle dependent…
Single-crystals of the new ferromagnetic superconductor UCoGe have been grown. The quality of as-grown samples can be significantly improved by a heat-treatment procedure, which increases the residual resistance ratio (RRR) from ~5 to ~30.…
The evolution of magnetic properties of isostructural and isoelectronic solid solutions of the superconducting itinerant 5f-electron ferromagnet UCoGe with antiferromagnet UIrGe was studied by magnetization, AC susceptibility, specific…
Heat capacity and anisotropic thermal expansion was measured for Ba(Fe_{1-x}Co_x)_2As_2 (x = 0, 0.038, 0.074) single crystals. Thermal expansion is anisotropic and, in tetragonal phase, is significantly higher along the c-axis. Previously…
Thermal conductivity measurements have been performed on the superconducting ferromagnet UCoGe down to very low temperature and under magnetic field. In addition to the electronic quasiparticle thermal conductivity, additional contributions…
We report the coexistence of ferromagnetic order and superconductivity in UCoGe at ambient pressure. Magnetization measurements show that UCoGe is a weak ferromagnet with a Curie temperature T_{C}= 3 K and a small ordered moment $m_{0}$=…
Recently, coexistence of ferromagnetism (T_Curie = 2.8K) and superconductivity (T_sc = 0.8K) has been reported in UCoGe, a compound close to a ferromagnetic instability at ambient pressure P. Here we present resistivity measurements under…
We have investigated a single crystal of CeAgSb2 using low field ac-susceptibility, thermal expansion and magnetostriction measurements in the temperature range 1.5K to 90K. The ac-susceptibility exhibits a sharp peak at 9.7K for both B//c…
We present high field magnetoresistance, Hall effect and thermopower measurements in the Ising-type ferromagnetic superconductor UCoGe. Magnetic field is applied along the easy magnetization $c$ axis of the orthorhombic crystal. In the…
We have performed 59Co NMR experiments on the ferromagnetic superconductor UCoGe under magnetic fields (H) along the a- and b- axes to investigate the relationship between ferromagnetic properties and superconductivity. The ferromagnetic…
The pressure-temperature phase diagram of the orthorhombic ferromagnetic superconductor UCoGe was determined by resistivity measurements up to $10.5~$GPa. The Curie temperature $T_C$ is suppressed with pressure and vanishes at the critical…
We present measurements of the thermal expansion coefficient alpha of polycrystalline LaFeAsO1-xFx (x <= 0.1). The magnetic and structural transitions of the samples with x <= 0.04 give rise to large anomalies in alpha(T), while the onset…