Related papers: Low frequency acoustics in solid $^4$He at low tem…
We have carried out torsional oscillator experiments on solid $^4$He at temperatures between 1.3K and 1.9K. We discovered phenomena similar to those observed at temperatures below 0.2K, which currently are under debate regarding their…
We have investigated the elastic properties of the Ce-based filled skutterudite antimonides CeRu$_{4}$Sb$_{12}$ and CeOs$_{4}$Sb$_{12}$ by means of ultrasonic measurements. CeRu$_{4}$Sb$_{12}$ shows a slight increase around 130 K in the…
We measured the elastic constants $\left(C_{11}-C_{12}\right)/2$ and $C_{44}$ of the non-Kramers system $\rm{Y_{0.63}Pr_{0.37}Ir_{2}Zn_{20}}$ (Pr-37% system) by means of ultrasound to check how the single-site quadrupolar Kondo effect is…
The material properties selection for designing acoustic filters with optimal performance over a range of frequencies requires considerable effort to fabricate and test laboratory samples. To simplify this procedure, one may test a single…
Inelastic and elastic neutron scattering have been used to study a single crystal of the Ni$_{54}$Mn$_{23}$Al$_{23}$ Heusler alloy over a broad temperature range. The paper reports the first experimental determination of the low-lying…
The wavelength and Einstein A coefficient are calculated for all rotation-vibration transitions of $^4$He$^1$H$^+$, $^3$He$^1$H$^+$, $^4$He$^2$H$^+$ and $^3$He$^2$H$^+$, giving a complete line list and the partition function for $^4$HeH$^+$…
The elastic constant tensors for the hcp phases of three transition metals (Co, Re, and Fe) are computed as functions of pressure using the Linearized Augmented Plane Wave method with both the local density and generalized gradient…
Relaxor ferroelectrics are difficult to study and understand. The experiment shows that at low energy scattering there is an acoustic mode, an optic mode, dynamic quasi-elastic scattering and strictly elastic scattering as well as Bragg…
We observe magnetic effects in ultra-high quality factor crystalline quartz Bulk Acoustic Wave resonators at milli-Kelvin temperature. The study reveals existence of hysteresis loops, jumps and memory effects of acoustical resonance…
We report on low-frequency current fluctuations, i.e. electronic noise, in quasi-one-dimensional (TaSe$_4$)$_2$I Weyl semimetal nanoribbons. It was found that the noise spectral density is of the 1/f type and scales with the square of the…
Crystal grains of solid $^4$He can move in relation to each other even when embedded inside the solid. In this work, we characterize a macroscopic motion of solid hcp $^4$He composed of such grains. Motion is induced by applying an external…
Recent experiments showed that the shear modulus of solid 4He stiffens in the same temperature range (below 200 mK) where mass decoupling and supersolidity have been inferred from torsional oscillator measurements. The two phenomena are…
The ab-plane reflectance of a Pr2CuO4 single crystal has been measured over a wide frequency range at a variety of temperatures, and the optical properties determined from a Kramers-Kronig analysis. Above ~ 250 K, the low frequency…
Besides the dynamical slowing down signaled by an enormous increase of the viscosity approaching the glass transition, structural glasses show interesting anomalous thermodynamic features at low temperatures that hint at peculiar deviations…
Plastic flow behavior of low carbon steel has been studied at room temperature during tensile deformation by varying the initial strain rate of 3.3x10e-4 1/sec to the final strain rate ranging from 1.33x10e-3 1/sec to 2.0x10e-3 1/sec at a…
Based on the many-boson system structure factor, which takes into account three- and four-particle direct correlations, there was found the first sound velocity temperature behaviour in liquid $^4$He in the post-RPA approximation. The…
A study by computer simulation is reported of the behaviour of a quantized vortex line at a very low temperature when there is continuous excitation of low-frequency Kelvin waves. There is no dissipation except by phonon radiation at a very…
We report on the measurements of 9.6 MHz ultrasound propagation down to 15 mK in polycrystalline quantum solid $^4$He containing 0.3 and 20 ppm $^3$He impurities. The attenuation and speed of ultrasound are strongly affected by the…
The speed of longitudinal sound waves at 7 and 22 MHz has been measured in liquid, supecooled, and amorphous selenium, including the region around the glass transition temperature, Tg, near 35 C. In amorphous selenium the speed of shear…
The temperature dependence of the elastic properties of antiferroelectric PbHfO3 was investigated by Brillouin scattering. The two structural phase transitions of antiferroelectric-antiferroelectric-paraelectric phases were clearly…