Glass-Like Phonon Dynamics and Thermal Transport in a GeTe Nano-Composite at Low Temperature.

In this work, the experimental evidence of glass-like phonon dynamics and thermal conductivity in a nanocomposite made of GeTe and amorphous carbon is reported, which is of interest for microelectronics, and specifically phase change memories. It is shown that, the total thermal conductivity is reduced by a factor of three at room temperature with respect to pure GeTe, due to the reduction of both electronic and phononic contributions. This latter, similarly to glasses, is small and weakly increasing with temperature between 100 and 300 K, indicating a mostly diffusive thermal transport and reaching a value of 0.

Rare Tumors in Children and Adolescents - the STEP Working Group's Evolution to a Prospective Registry.

Background Very rare tumors (VRT) in children and adolescents have such a low incidence that until recently, they have not been integrated into the clinical and scientific network of pediatric oncology. Data is very limited and consistent treatment strategies are missing. Thus, VRTs are classic orphan diseases.

Impact of Stoichiometry on the Structure of van der Waals Layered GeTe/Sb Te Superlattices Used in Interfacial Phase-Change Memory (iPCM) Devices.

Van der Waals layered GeTe/Sb Te superlattices (SLs) have demonstrated outstanding performances for use in resistive memories in so-called interfacial phase-change memory (iPCM) devices. GeTe/Sb Te SLs are made by periodically stacking ultrathin GeTe and Sb Te crystalline layers. The mechanism of the resistance change in iPCM devices is still highly debated.

Testicular sex cord stromal tumors: analysis of patients from the MAKEI study.

Background: In children and adolescents, testicular sex cord stromal tumors (TSCSTs) are rare. There is only limited information available regarding their clinical presentation, biology, and prognosis.

Methods: Between 1993 and 2009, 42 patients were prospectively reported to the cooperative MAHO and MAKEI studies on childhood germ cell tumors.

Iron dynamics in Al-Cu-Fe quasicrystals and approximants: Mössbauer and neutron experiments.

We present new results on the iron dynamics in the icosahedral quasicrystal i-AlCuFe and two cubic approximants as well as the non-approximant Al-Cu-Fe cubic B2 phase. Conventional Mössbauer spectroscopy is used as well as, for the i-AlCuFe phase, high Doppler velocity Mössbauer spectroscopy and quasielastic neutron scattering for samples with different Fe isotope contents. We show that in the i-phase the Fe Lamb-Mössbauer recoilless fraction decreases below that predicted for lattice vibrations alone for temperatures above about 550 K.

Hidden magnetic frustration by quantum relaxation in anisotropic Nd langasite.

The static and dynamic magnetic properties of the Nd(3)Ga(5)SiO(14) compound, which appears as the first materialization of a rare-earth kagome-type lattice, were reexamined, owing to contradictory results in the previous studies. Neutron scattering, magnetization, and specific heat measurements were performed and analyzed, in particular, by fully taking account of the crystal electric field effects on the Nd(3+) ions. One of the novel findings is that the peculiar temperature independent spin dynamics observed below 10 K expresses single-ion quantum processes.