Magnetization and sound propagation studied on a high-quality single crystal of ferrimagnetic compound TmFe5Al7 in high magnetic fields up to 60 Tesla reveal very unusual combination of spontaneous and field-induced transitions as the Tm provides an uniaxial magnetic anisotropy, whereas Fe favors an easy-plane anisotropy. This competition results in a omplex scenario of magnetic order including in-plane antiferromagnetic phase embedded in low and high temperature ferrimagnetic phases.
Optical gold elements coated with diamond layers with flat, nanocolumnar, and nanoporous morphologies. Fabricated diamond coated optical elements were successfully used for the grazing angle reflectance FTIR characterization of fetal bovin serum (FBS) proteins adsorbed on the O-terminated diamond surface. In spite of the different processing and structuring, all types of diamond layers showed good stability, uniformity, and optical properties, including good reflectivity of the gold mirrors.
The influence of laser frequency on laser-driven ion acceleration is investigated by means of twodimensional particle-in-cell simulations. When ultrashort intense laser pulse at higher harmonic frequency irradiates a thin solid foil, the target may become relativistically transparent for significantly lower laser pulse intensity compared with irradiation at fundamental laser frequency. The relativistically induced transparency results in an enhanced heating of hot electrons as well as increased maximum energies of accelerated ions and their numbers.
In this paper, new steps toward a etter understanding and utilization of high-pressure high-temperature nanodiamonds (NDs) containing nitrogen-vacancy (NV) centers have been taken. NV–-related long-term luminescence of oxygenated particles increased in comparison to plasma hydrogenated NDs’ NV– luminescence. The optically detected NV– electron spin resonance process can be also significantly affected by ND termination.
We developed an original fully relativistic ab initio theory of anomalous Hall effect for disordered ferromagnetic alloys with simple and complex lattice structure. The theory was applied to elementary ferromagnets (Fe, Co, Ni), their alloys (NiFe, FeSi), to partially ordered FePt alloys and to selected Heusler alloys in a good agreement with experiment. Anomalous Hall effect in Heusler alloys is important for prospective applications in spintronics.
We prepare InGaN/GaN multiple quantum well (MQW) structure by metal–organic vapor phase epitaxy (MOVPE) and characterize it by XRD, photoluminescence and radioluminescence measurements. We demonstrated its suitability for scintillator application by an unique measurement
Properties of the plasma plume produced on a Bi target irradiated by a focused extreme-ultraviolet capillary-discharge laser beam were investigated. Langmuir probes were used to determine the electron temperature and the electron density, providing values of 1–3 eV and ~1013–1014 m−3, respectively. Although the temperatures seem to be comparable with values obtained in ablation plasmas produced by conventional lasers, the density is significantly lower.
Mg-codoped Lu3Al5O12:Ce single crystal garnet scintillators were prepared with a wide concentration range 0–3000 ppm of Mg2+. Luminescence and scintillation characteristics were measured revealing the beneficial effect of Mg codoping which consists in stabilization of Ce4+ center. We propose a model explaining the mechanism of material improvement; the stable Ce4+ center provides an additional fast radiative recombination pathway in the scintillation mechanism.
Currently, interest in biomedical applications of low temperature plasmas is rapidly growing. However, the understanding of the molecular mechanisms behind low temperature plasma cellular effects remains a significant challenge. In a recent study, we showed how different low temperature plasmas induce cell death via the formation of multiple intracellular reactive oxygen/nitrogen species. Our results suggest that the biological response to low temperature plasma treatment greatly depends on: cell type, chemical composition of plasma and exposition length.
It is shown that spatial correlation functions measured for correlated photon pairs at the single-photon level correspond to speckle patterns visible at high intensities. This correspondence is observed for the first time in one experimental setup by using different acquisition modes of an intensified CCD camera in low and high intensity regimes. The behavior of intensity auto- and cross-correlation functions in dependence on pump beam parameters including power and transverse profile is investigated.
FEEDIT.CZ, 12.5.2018.
Historicky první, mimořádně slavnostní,...
Grantová agentura ČR, 7.5.2018.
Možnost zobrazit jednotlivé...
NOVINKY.CZ, 19.4.2018.
Dvanáct nadaných středoškoláků si bude...
Prague Daily Monitor, 6.3.2018.
Czech astronomer Martin Masek...
