Relaxation of radiative defects in irradiated triglycine sulfate

Nonmonotonic temporal behavior of the temperature dependence of the conductivity of ferroelectric triglycine sulfate is observed after its irradiation by small doses of x radiation. Such behavior is associated primarily with the formation of two types of radiation defects having different lifetimes. Fiz. Tverd. Tela (St. Petersburg) 40, 116–117 (January 1998)     

Annealing of radiation-induced defects in ion-implanted AIIBVI single crystals

The basic characteristics of annealing of implanted layers of A^II-B^VI compounds are studied. The equilibrium, quasiequilibrium, and nonequilibrium methods of annealing were employed. Equilibrium annealing was conducted in the saturated vapor of the metalloid at temperatures below the critical temperature, above which intense self-compensation processes start (T_cr 450–500°C for ZnS and ZnSe). If T_ann must be higher than T_cr owing to radiation-induced damage that is difficult to anneal, than the method of annealing under an active protective film was employed. For ZnSe and ZnS with an implanted acceptor impurity the protective film consisted of gold or silver sputtered on the crystal prior to annealing. Thus implantation of ions enabled obtaining layers of p-type ZnS with resistivities of 10²–10³ ·cm. The ZnSe layers with hole conductivity were also obtained with electron annealing under a protective gold film with weak-current beams with durations of several seconds. Quasiequilibrium annealing was conducted in the activated vapor of the metalloid. The vapor was activated by a high-frequency discharge in the vapor of the metalloid. This method of annealing gave sharp p-n junctions on implanted ZnSe. Pulsed electron beams were employed for nonequilibrium annealing.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 51–56, March, 1989.     

Perturbed angular correlation study of radiation-induced defects in Rh metal

Radiation-induced defects are studied in cubic rhodium metal, using the local probe technique ‘Time differential perturbed angular correlation’ (TDPAC) at liquid N₂ temperature. Isochronal annealing was done at 300, 1073 and 1473 K temperatures. The irradiated sample showed two quadrupole interaction frequencies at 1150 and 93 MHz. The low frequency disappeared at room-temperature annealing, which was assigned to In trapped at a vacancy, whereas the higher frequency remained up to high temperatures and was attributed to In trapped at Rh–C complexes in the Rh matrix.     

Mechanism of interconversion among radiation-induced defects in amorphous silicon dioxide

We here present a series of ab initio quantum-chemical calculations on clusters of atoms modeling several oxygen-deficiency-related defects in amorphous silica and illustrate how these defect centers will change their atomic configurations upon photoionization. We first give theoretical evidence that structural conversion from a neutral oxygen monovacancy to a divalent Si defect is possible, explaining the observed photoluminescence properties associated with these defects.     

快冷Fe-Al合金中的原子缺陷弛豫

在多功能内耗仪上用自由衰减和强迫振动方法研究了不同Al含量淬火Fe-Al合金中的两个弛豫型内耗峰.结果显示：P1(180℃)和P2(340℃)两个内耗峰只出现在淬火样品的加热过程中,而在随后的冷却过程中不出现.P1峰是由在α和β(或γ)点阵上的空位组成的最近邻双空位偶极子在应力诱导下的重新取向产生的,其弛豫强度随Al含量非单调地变化,在大约25% Al(原子百分比,以下同)处出现最大值.Al含量较低的Fe-Al合金无 关键词： 空位 弛豫 Al含量     

快冷Fe-Al合金中的原子缺陷弛豫

在多功能内耗仪上用自由衰减和强迫振动方法研究了不同Al含量淬火Fe-Al合金中的两个弛豫型内耗峰.结果显示：P1(180℃)和P2(340℃)两个内耗峰只出现在淬火样品的加热过程中，而在随后的冷却过程中不出现.P1峰是由在α和β(或γ)点阵上的空位组成的最近邻双空位偶极子在应力诱导下的重新取向产生的，其弛豫强度随Al含量非单调地变化，在大约25% Al(原子百分比，以下同)处出现最大值.Al含量较低的Fe-Al合金无     

Relaxation kinetics of primary pairs of radiation defects in ionic crystals

The relaxation kinetics of primary pairs of radiation defects in ionic crystals with a face-centered lattice is investigated using the Monte Carlo method. The dependence of the relaxation kinetics of an F-H pair on the parameters of the interaction potential between the components of the pair is studied. The obtained kinetic dependences are analyzed to determine the factors responsible for the relaxation processes.     

Relaxation processes in the incommensurate phase of a crystal with defects

The nature of the relaxation of the incommensurate superstructure of a ferroelectric to the equilibrium state is investigated experimentally. It is shown that near a phase transition the temperature dependence of the relaxation time of the incommensurate phase of the defective crystal is exponential. This law agrees qualitatively with the notion of domain wall motion in an inhomogeneous medium containing “random local phase-transition temperature” type defects. Fiz. Tverd. Tela (St. Petersburg) 41, 513–515 (March 1999)     

Mechanisms of radiation-induced viscous flow: role of point defects

Mechanisms of radiation-induced flow in amorphous solids have been investigated using molecular dynamics computer simulations. It is shown for a model glass system, CuTi, that the radiation-induced flow is independent of recoil energy between 100 eV and 10 keV when compared on the basis of defect production and that there is a threshold energy for flow of approximately 10 eV. Injection of interstitial- and vacancylike defects induces the same amount of flow as the recoil events, indicating that point-defect-like entities mediate the flow process, even at 10 K. Comparisons of these results with experiments and thermal spike models are made.     

Reduction of the annealing temperature of radiation-induced defects in ion-implanted MOS structures

Si-SiO₂ structures irradiated with 11-MeV electrons for 10 s and then implanted with B⁺ ions with an energy of 10 keV at a dose of 1.0×10¹² cm^-2 through the oxide were annealed at different temperatures. MOS capacitors including such oxide layers were studied by quasi-static C/V and thermally stimulated current (TSC) methods. A comparison of the radiation defect annealing of double-treated (electron-irradiated and ion-implanted) samples and of implanted-only samples was carried out. It is shown that a preceding low-dose high-energy electron irradiation of the samples leads to a lowering of the annealing temperature of radiation defects introduced by ion implantation. After annealing at 500 °C for 15 min, no TSC spectra for the double-treated samples were observed. The spectra of the other samples (which were not previously irradiated) showed that after the same thermal treatment only some of the radiation defects introduced by ion implantation are annealed. The difference between the annealed interface state density of previously electron-irradiated and current MOS structures is also demonstrated. A possible explanation of the results is proposed . PACS 61.82.Fk; 85.40.Ry; 61.80.Fe     

Electrical activity of radiation-induced defects in indium antimonide and arsenide surface-barrier structures

The electrical activity of defects induced by high-energy proton irradiation inInSb andInAs semiconductors is investigated by etching from their surfaces a layer whose thickness is equal to the depth of defect localization and preparing a MOS structure. Two layers of defects of different origin and electrical are detected, and their influence on the surface-state energy spectrum, the recombination activity, and the kinetic characteristics of the defective layer is revealed. The threshold increase in the photosensitivity and the speed of performance and vanishing of the burst noise in MOS structures are found. The results obtained are explained for a model of conservation of the local electrical neutrality that specifies the position of the Fermi energy levels in irradiated semiconductors. Tomsk State University of Control Systems and Radioelectronics. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 37–45, September, 1999.