A novel method for obtaining position resolved information simultaneously from an entire plane of a polycrystalline or amorphous sample using the diffracted radiation or fluorescence has been developed. It makes use of a microchannelplate as a collimator in front of a position sensitive detector (CCDcamera). Experiments may be performed either in transmission or in reflection geometry. In the f...

2014 It is shown that scalar, stress induced contributions to the elastic energy, which are not explicitly rotationally invariant can play an important rôle in determining the elastic properties of tenuous structures. Recent scaling results are used to show that the scalar contributions tend to be dominant at criticality It is argued that liquid-like hydrostatic stresses are large and will tend...

Yielding transitions in athermal amorphous materials undergoing steady-state shear flow resemble critical phenomena. Historically, they have been described by the Herschel-Bulkley rheological formula, which implies singular behaviors at yield points. In this paper, I examine this class of phenomena using an elementary version of the thermodynamic shear-transformation-zone (STZ) theory, focusing...

We develop a theory of the effective disorder temperature in glass-forming materials driven away from thermodynamic equilibrium by external forces. Our basic premise is that the slow configurational degrees of freedom of such materials are weakly coupled to the fast kinetic-vibrational degrees of freedom and therefore that these two subsystems can be described by different temperatures during d...

We briefly review the electrical-optical response of materials to radiative forcing within the formalism of the Kramers-Kronig relations. A commensurate set of criteria is described that must be met by any frequency-domain model representing the time-domain response of a real (i.e., physically possible) material. The criteria are applied to the Brendel-Bormann (BB) oscillator, a model that was ...

Erbium (Er) ion has been widely used in silica fiber-based active photonic devices, given its characteristic emission around 1.5 μm. Hydrogenated and deuterated amorphous carbon (a-C:H and a-C:D, respectively), thin film materials offering tailorable opto-electronic properties, have not been explored thoroughly as host materials for Er. The objective of this research is to study the potential s...

Poly(L-lactic acid), PLLA, in amorphous and semi-crystalline forms were studied by DSC, in order to investigate both molecular dynamics and structural relaxation features, and to understand the influence of the crystalline confinement on the segmental mobility of the intraspherulitic amorphous phase. Experimental data were generated after submitting the materials to different thermal histories ...

Nanotube/matrix interfacial friction and sliding in composites with an amorphous carbon matrix L. Li, J.B. Niu, Z.H. Xia,a,⇑ Y.Q. Yang and J.Y. Liang Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA School of Materials, Northwestern Polytechnic University, Xi’an, People’s Republic of China Department of Mechanical Engineering, Worcester Polytechn...

Isaeva, L. 2015. Amorphous and crystalline functional materials from first principles. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1276. 105 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9311-0. This thesis deals with various functional materials from first-principles methods and is divided into two major parts according to ...

Amorphous oxide semiconductors based on indium oxide [e.g., In–Zn–O (IZO) and In–Ga–Zn–O (IGZO)] are of interest for use in thin-film transistor (TFT) applications. We report that the stability of amorphous In–Zn–O (a-IZO) used in TFT applications depends, in part, on the metallization materials used to form the source and drain contacts. A thermodynamics-based approach to the selection of IZO ...