Related papers: Dopant concentration effects on Si$_{1-x}$Ge$_{x}$…
We present high energy x-ray (67 keV) and neutron scattering measurements on a single crystal of K$_{1-x}$Li$_x$TaO$_3$ for which the Li content ($x=0.02$) is less than $x_c = 0.022$, the critical value below which no structural phase…
Heavily-doped semiconductor films are very promising for application in mid-infrared plasmonic devices because the real part of their dielectric function is negative and broadly tunable in this wavelength range. In this work we investigate…
We have explored the light induced dynamics in superfluid helium nanodroplets with wide-angle scattering in a pump-probe measurement scheme. The droplets are doped with xenon atoms to facilitate the ignition of a nanoplasma through…
We report on the results of molecular dynamics simulation (MD) studies of the classical two-dimensional electron crystal in the presence disorder. Our study is motivated by recent experiments on this system in modulation doped semiconductor…
We present a study of germanium as n-type dopant in wurtzite GaN films grown by plasma-assisted molecular beam epitaxy, reaching carrier concentrations of up to 6.7E20 cm-3 at 300K, well beyond the Mott density. The Ge concentration and…
We report on a thorough optical investigation over a broad spectral range and as a function of temperature of the charge dynamics in Ba(Co$_x$Fe$_{1-x}$)$_2$As$_2$ compounds for Co-doping ranging between 0 and 18%. For the parent compound…
Polarized inelastic light scattering experiments on Cu_(1-x)Zn_xGeO_3 (0<= x <= 0.045) single crystals show for x<>0 a new distinct mode at nearly half the energy of the singlet response below the spin-Peierls transition. The temperature,…
The temperature dependence of the London penetration depth $\Delta\lambda(T)$ in the superconducting doped topological crystalline insulator Sn$_{1-x}$In$_x$Te was measured down to 450 mK for two different doping levels, x $\approx$ 0.45…
The kinetics of intrinsic and dopant-enhanced solid phase epitaxy (SPE) is stud- ied in amorphous germanium (a-Ge) layers formed by ion implantation on <100> Ge substrates. The SPE rates were measured with a time-resolved reflectivity (TRR)…
We analyze Ge-related defects in Ge-doped SiO_2 using first-principles density functional techniques. Ge is incorporated at the level of ~ 1 mol % and above. The growth conditions of Ge:SiO_2 naturally set up oxygen deficiency, with vacancy…
The percentage of substitutional doping of magnetic atoms (Mn) in group-IV-based dilute magnetic semiconductors (DMS) can be increased by co-doping with another conventional electronic dopant (e-dopant) [Zhu et al., Phys. Rev. Lett. 100,…
Germanium (Ge), the next-in-line group-IV material, bears great potential to add functionality and performance to next-generation nanoelectronics and solid-state quantum transport based on silicon (Si) technology. Here, we investigate the…
Previous investigations of 4$H_b$-TaS$_{2-2x}$Se$_{2x}$ mainly focused on the direct competition between superconductivity and charge density wave (CDW). However, the superconductivity itself, although has been prominently enhanced by…
Chemical substitution plays a key role in controlling the electronic and magnetic properties of complex materials. For instance, in EuO, carrier doping can induce a spin-polarized metallic state, colossal magnetoresistance, and…
In this article we present some particularly important issues regarding the CeCo$_{1-x}$Fe$_{x}$Ge$_{3}$ alloys. Firstly, the electrical resistivity below 2 K, down to 500 mK is studied to confirm the non-Fermi-liquid behavior around the…
We present a density-functional theory (DFT) study of the structural, electronic, and chemical bonding behaviour in germanium (Ge)-doped vanadium dioxide (VO$_2$). Our motivation is to explain the reported increase of the metal-insulator…
Photo- and thermally stimulated luminescence characteristics of Gd3(Ga,Al)5O12:Ce single crystals co-doped with W and Mo are investigated in the 85 - 510 K temperature range and compared with the corresponding characteristics of the undoped…
Single crystal neutron diffraction is used to investigate the magnetic and structural phase diagram of the electron doped superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$. Heat capacity and resistivity measurements have demonstrated that Co…
Flexoelectricity, an electromechanical coupling between strain gradient and polarization, offers a promising dimension to enrich silicon-based devices. Although the flexoelectricity of silicon is known, some fundamental aspects remain…
We investigate the effects of transition metals (TM) on the electronic doping and scattering in graphene using molecular beam epitaxy combined with in situ transport measurements. The room temperature deposition of TM onto graphene produces…