Analysis of the Metallic Phase of Two-Dimensional Holes in SiGe in Terms of Temperature Dependent Screening

We find that temperature dependent screening can quantitatively explain the metallic behaviour of the resistivity on the metallic side of the so-called metal-insulator transition in p-SiGe. Interference and interaction effects exhibit the usual insulating behaviour which is expected to overpower the metallic background at sufficiently low temperatures. We find empirically that the concept of a Fermi-liquid describes our data in spite of the large r_s = 8.Comment: 4 pages, 3 figure

Anisotropic nanomaterials: structure, growth, assembly, and functions

Comprehensive knowledge over the shape of nanomaterials is a critical factor in designing devices with desired functions. Due to this reason, systematic efforts have been made to synthesize materials of diverse shape in the nanoscale regime. Anisotropic nanomaterials are a class of materials in which their properties are direction-dependent and more than one structural parameter is needed to describe them. Their unique and fine-tuned physical and chemical properties make them ideal candidates for devising new applications. In addition, the assembly of ordered one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) arrays of anisotropic nanoparticles brings novel properties into the resulting system, which would be entirely different from the properties of individual nanoparticles. This review presents an overview of current research in the area of anisotropic nanomaterials in general and noble metal nanoparticles in particular. We begin with an introduction to the advancements in this area followed by general aspects of the growth of anisotropic nanoparticles. Then we describe several important synthetic protocols for making anisotropic nanomaterials, followed by a summary of their assemblies, and conclude with major applications

The romance of navigation, edited by Francis E. McMurtrie. Foreword by Captain E.R.G.R. Evans.

Mode of access: Internet

Anderson universality in a model of disordered phonons

We consider the localisation properties of a lattice of coupled masses and springs with random mass and spring constant values. We establish the full phase diagrams of the system for pure mass and pure spring disorder. The phase diagrams exhibit regions of stable as well as unstable wave modes. The latter are of interest for the instantaneous-normal-mode spectra of liquids and the nascent field of acoustic metamaterials. We show the existence of delocalisation-localisation transitions throughout the phase diagram and establish, by high-precision numerical studies, that the universality of these transitions is of the Anderson type

TEM analysis of Si-passivated Ge-on-Si MOSFET structures for high performance PMOS device technology

In this paper, we present a transmission electron microscopy analysis of novel Ge-on-Si MOSFETs using a JEOL 2010F and an aberration-corrected JEOL 2200FSC. A key feature of these devices is the incorporation of a very thin (~1nm) Si passivation layer on top of the Ge virtual substrate, which is partially oxidised to form SiO2 (~0.5nm) prior to depositing HfO2 dielectric. We will show that the thin SiO2 layer is not purely amorphous but has some degree of crystal ordering due to being bonded to crystalline materials. Moreover, we will examine the presence of small monolayer variation in Si/SiO2 interface roughness

TEM analysis of Ge-on-Si MOSFET structures with HfO2dielectric for high performance PMOS device technology

In this paper, we present a (scanning) transmission electron microscopy analysis of novel Ge-on-Si MOSFETs which incorporate a high-k HfO2 dielectric and TaN/TiN metal gate electrodes. A key feature of these devices is the incorporation of a very thin (~1nm) Si passivation layer on top of the Ge virtual substrate, which is partially oxided to form SiO2 (~0.5nm), before depositing the HfO2 dielectric and TaN and TiN metal gate electrodes. Our results confirm the architecture of the device structures and the existence of Si passivation