Physics

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The fabrication of Ge-doped light-emitting devices in single-crystal α-quartz without destroying its crystal structure via the dynamic solid phase epitaxial regrowth technique is being pursued. This paper presents results on the cathodoluminescence (CL) after 120 keV Ge implantation in α-quartz at 1173 K with fluences between 1 × 1014 and 1 × 1016 ions/cm2. Rutherford backscattering-channeling analysis showed that the Ge implantation up to 4 × 1014 ions/cm2 produced isolated damage zones. The transition to an amorphous layer is accompanied by a strong increase in the CL output. The CL spectra taken at 10-300 K show six bands located at 260 nm (4.9 eV, UV), 288 nm (4.3 eV, UV), 383 nm (3.1 eV, violet), 453 nm (2.7 eV, blue), 511 nm (2.4 eV, green) and 620 nm (2.0 eV, red). Only the violet band is associated with the Ge-related defects or the formation of Ge-clusters; it reaches its maximum intensity at 7 × 1014 Ge-ions/cm 2. All the other bands are connected to various defect centers in the SiO2 network. © 2003 Elsevier B.V. All rights reserved.

World University root node

(SoNS) School of Natural Sciences

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

Cathodoluminescence of α-quartz after hot Ge ion irradiation

Physical Review B

Ab initio Wannier-function-based many-body approach to Born charges of crystalline insulators

Fulltext

Journal of Applied Physics

X-ray absorption spectroscopy of transition-metal doped diluted magnetic semiconductors Zn1-xMxO

The photo-generated time-of-flight electron mobility measurements in 2,5-dibenzthiazolyl thiophene show weak field dependent high electron mobility, typically of the order of 1.21 × 10-4 cm2/Vs at 2.5 × 105 V/cm, which is two orders of magnitude higher than that of Alq3 complex. © 2004 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.

Physica Status Solidi (A) Applied Research

Photo-generated time-of-flight mobility measurements in novel electron transport material: 2,5-dibenzthiazolyl thiophene

The origin of ferromagnetism in a metastable phase rather than by carrier-induced interaction between separated Mn atoms in ZnO in a low-temperature-processed MnO2-ZnO system was demonstrated. It was observed that the ferromagnetism persists up to ∼980 K. It was shown that a uniform solution of Mn in ZnO does not form under low-temperature processing. The direct low-temperature film growth of Zn-incorporated Mn oxide shows ferromagnetism at low Zn concentration for an optimum oxygen growth pressure.

Nature Materials

On the origin of high-temperature ferromagnetism in the low-temperature-processed Mn-Zn-O system

Chemically guided solid phase epitaxy of α-quartz after Rb +-ion implantation and thermal annealing in 18O 2 was studied in order to clarify the role of the alkali ions and oxygen during this process. In particular, the influence of the 18O2 gas pressure and Rb+-ion fluence was investigated via Rutherford Backscattering Channeling and Time-of-Flight Elastic Recoil Detection techniques. Complete or partial epitaxy was observed, depending on the Rb-fluence, annealing temperature, and oxygen pressure. The recrystallization rate increased with increasing ion fluence, while the oxygen pressure had only little influence on the recovery process. Among these three parameters, the annealing temperature plays the most important role. © 2003 Elsevier B.V. All rights reserved.

Chemically guided epitaxy of Rb-ion amorphized α-quartz: The roles of Rb and oxygen

In the course of a systematic investigation of heavy ion-irradiated Fe/Si layers, we have studied atomic transport and phase formation induced by 22-keV 14N2+ ion implantation in 57Fe(30 nm)/Si bilayers at high fluences. We report here results obtained by Rutherford backscattering spectroscopy, X-ray diffraction, and conversion electron Mössbauer spectroscopy after implantation and post-implantation annealing treatments. The irradiations caused little sputtering, but significant interface mixing. During implantation, iron nitrides, but no silicides were formed, even at the highest nitrogen fluence of 2 × 1017 ions/cm 2. When heating these samples in vacuo up to 700°C, the iron-rich phases ε-Fe3N and γ-Fe4N were produced. Starting at 600°C the suicide phase β-FeSi2 was also identified.

Applied Physics A: Materials Science and Processing

Nitrogen irradiation of Fe/Si bilayers: Nitride versus suicide phase formation

A one-dimensional Schrödinger equation with position-dependent effective mass in the kinetic-energy operator is studied in the framework of an so(2,1) algebra. New mass-deformed versions of Scarf II, Morse, and generalized Pöschl-Teller potentials are obtained. Consistency with the intertwining condition is pointed out.

Czechoslovak Journal of Physics

Effective-mass Schrödinger equation and generation of solvable potentials

We show that the conditionally exactly solvable potential of Dutt et al (1995 J.Phys. A: Math. Gen. 28 L107) and the exactly solvable potential from which it is derived form a dual system.

Journal of Physics A: Mathematical and General

Conditionally exactly solvable potential and dual transformation in quantum mechanics

Physical Review-Section B-Condensed Matter

RAPID COMMUNICATIONS-Electronic structure: Wide-band, narrow-band, and strongly correlated systems-Ab initio Wannier-function-based many-body approach to Born charges of crystalline insulators (4