Crystal Structure Of Lt Gaas Layers Before And After Annealing

1991 ◽  
Vol 241 ◽  
Author(s):  
Zuzanna Liliental-Weber
Keyword(s):  
Growth Temperature ◽  
Growth Conditions ◽  
Structural Defects ◽  
Structural Quality ◽  
Before And After ◽  
Formation Energies ◽  
Insulating Properties ◽  
Minority Carriers

ABSTRACTThe structural quality of GaAs layers grown at low temperatures by solid-source and gassource MBE at different growth conditions is described. Dependence on the growth temperature and concentration of As [expressed as As/Ga beam equivalent pressure (BEP)] used for the growth is discussed. A higher growth temperature is required to obtain the same monocrystalline layer thickness with increased BEP The annealing of these layers is associated with the formation of As precipitates. Semicoherent precipitates with lowest formation energies arc formed in the monocrystalline parts of the layers grown with the lowest BEP. Precipitates with higher bormation energies are formed when higher BEP is applied; they are also formed in the vicinity of structural defects. Formation of As precipitates releases strain in the layers. Arsenic precipitates are not formed in annealed ternary (InAlAs) layers despite their semi-insulating properties. The role of As precipitates in semi-insulating properties and the short lifetime of minority carriers in these layers is discussed.

Structure and Orientation of As Precipitates in LT-MBE Grown GaAs

1991 ◽  
Vol 49 ◽  
pp. 900-901 ◽  
Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber
Keyword(s):  
Transport Properties ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Lattice Parameter ◽  
Crystalline Quality ◽  
Insulating Properties ◽  
Lt Gaas

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

ВЛИЯНИЕ ТВЕРДОФАЗНОЙ РЕКРИСТАЛЛИЗАЦИИ С ДВОЙНОЙ ИМПЛАНТАЦИЕЙ НА ПЛОТНОСТЬ СТРУКТУРНЫХ ДЕФЕКТОВ В УЛЬТРАТОНКИХ СЛОЯХ КРЕМНИЯ НА САПФИРЕ

2020 ◽  
Vol 96 (3s) ◽  
pp. 154-159
Author(s):  
Н.Н. Егоров ◽  
С.А. Голубков ◽  
С.Д. Федотов ◽  
В.Н. Стаценко ◽  
А.А. Романов ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Solid Phase ◽  
Modern Method ◽  
Structural Defects ◽  
Structural Quality ◽  
Mos Transistors ◽  
Ultrathin Layers ◽  
Heteroepitaxial Layers ◽  
Xrd And Tem

Высокая плотность структурных дефектов является основной проблемой при изготовлении электроники на гетероструктурах «кремний на сапфире» (КНС). Современный метод получения ультратонких структур КНС с помощью твердофазной эпитаксиальной рекристаллизации позволяет значительно снизить дефектность в гетероэпитаксиальном слое КНС. В данной работе ультратонкие (100 нм) слои КНС были получены путем рекристаллизации и утонения субмикронных (300 нм) слоев кремния на сапфире, обладающих различным структурным качеством. Плотность структурных дефектов в слоях КНС оценивалась с помощью рентгеноструктурного анализа и просвечивающей электронной микроскопии. Кривые качания от дифракционного отражения Si(400), полученные в ω-геометрии, продемонстрировали максимальную ширину на полувысоте пика не более 0,19-0,20° для ультратонких слоев КНС толщиной 100 нм. Формирование структурно совершенного субмикронного слоя КНС 300 нм на этапе газофазной эпитаксии обеспечивает существенное уменьшение плотности дислокаций в ультратонком кремнии на сапфире до значений ~1 • 104 см-1. Тестовые n-канальные МОП-транзисторы на ультратонких структурах КНС характеризовались подвижностью носителей в канале 725 см2 Вс-1. The high density of structural defects is the main problem on the way to the production of electronics on silicon-on-sapphire (SOS) heteroepitaxial wafers. The modern method of obtaining ultrathin SOS wafers is solid-phase epitaxial recrystallization which can significantly reduce the density of defects in the SOS heteroepitaxial layers. In the current work, ultrathin (100 nm) SOS layers were obtained by recrystallization and thinning of submicron (300 nm) SOS layers, which have various structural quality. The density of structural defects in the layers was estimated by using XRD and TEM. Full width at half maximum of rocking curves (ω-geometry) was no more than 0.19-0.20° for 100 nm ultra-thin SOS layers. The structural quality of 300 nm submicron SOS layers, which were obtained by CVD, depends on dislocation density in 100 nm ultrathin layers. The dislocation density in ultrathin SOS layers was reduced by ~1 • 104 cm-1 due to the utilization of the submicron SOS with good crystal quality. Test n-channel MOS transistors based on ultra-thin SOS wafers were characterized by electron mobility in the channel 725 cm2 V-1 s-1.

scholarly journals Golgi-Colonnier method: correlation of the degree of chromium reduction and pH change with quality of staining.

1994 ◽  
Vol 42 (3) ◽  
pp. 393-403 ◽  
Author(s):  
A Angulo ◽  
J A Merchán ◽  
M Molina
Keyword(s):  
Chromium Reduction ◽  
Ph Change ◽  
Total Chromium ◽  
Chromium Species ◽  
Cell Staining ◽  
Before And After ◽  
Neuronal Proteins ◽  
Ph Increase

We examined the role of chromium reduction in the Golgi-Colonnier method, correlating the quality of neuronal impregnation with the levels of hexavalent (CrVI) and trivalent (CrIII) chromium in the tissue and in the chromation fluid (CF). The concentrations of both chromium species were assessed by measuring spectrophotometrically the CrVI before and after oxidizing the sample and by calculating the ratio of CrVI to total chromium (chromium ratio, CrR). The CrR was almost identical in the tissue and the CF, decreasing exponentially during chromation due to a progressive consumption of CrVI to form CrIII. Satisfactory cell impregnation was obtained only when the CrR was 0.45-0.7, regardless of other factors. The CrR values could be accurately predicted by the pH increase of the CF; this increase has proven to be a most reliable criterion to decide the endpoint of the chromation process. The dependence of cell staining on the [CrIII], together with the well-known ability of this species to bridge proteins, suggests that the key event for cell impregnation is the cross-linking of neuronal proteins by CrIII polymers.

scholarly journals Role of voiding and storage symptoms for the quality of life before and after treatment in men with voiding dysfunction

2009 ◽  
Vol 28 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Petros Sountoulides ◽  
Marleen M. van Dijk ◽  
Hessel Wijkstra ◽  
Jean J. M. C. H. de la Rosette ◽  
Martin Christian Michel
Keyword(s):  
Quality Of Life ◽  
Voiding Dysfunction ◽  
Before And After ◽  
And Storage

scholarly journals KEBIJAKAN PENYELENGGARAAN PENDIDIKAN TINGGI (Studi Tentang Peran Sistem Informasi Akademik Dalam Penyelenggaran Pendidikan Tinggi Di STKIP PGRI Bangkalan)

2018 ◽  
Vol 16 (1) ◽  
pp. 16
Author(s):  
Agoeng Koerniawan SA
Keyword(s):  
Higher Education ◽  
Information System ◽  
Information Systems ◽  
Teaching And Learning ◽  
Process Data ◽  
Quality Of Higher Education ◽  
Before And After ◽  
Academic Information

The purpose of this study was to determine the role of academic information systems in improving the quality of higher education implementation in PGRI STKIP Bangkalan, and the extent to which the policies of implementing higher education before and after the use of information systems and how satisfaction is felt by students towards academic information systems at STKIP PGRI Bangkalan, named STKIP PGRI Bangkalan’s Siakad.The study was conducted by conducting a survey of users of the internet-based academic information system (Siakad STKIP PGRI Bangkalan), namely lecturers, students and employees with the method of observation and conducting in-depth interviews to obtain as much information as possible from all respondents/informants. The number of informants was 5 people consisting of the chairman of STKIP PGRI Bangkalan, Vice Chairman I, Head of BAAK and two students who had experience in their respective fields of work, knew deeply and had many roles in the process of using information systems.Based on the results of the study, it was shown that with the use of the information system/ STKIP PGRI Bangkalan’s Siakad which is one of the facilities for the smooth activities of the teaching and learning process, it proved to provide convenience, many benefits and benefits that greatly support the duties of serving lecturers, students and outsiders requiring. This is evidenced by the support of the support of lecturers and students, capacity, namely the ability of employees to process data and value, namely the benefits felt by lecturers, employees and students as well as outside parties in need.

scholarly journals Emotions in leaders’ enactment of professional agency

2019 ◽  
Vol 31 (2) ◽  
pp. 143-165 ◽  
Author(s):  
Päivi Hökkä ◽  
Katja Vähäsantanen ◽  
Susanna Paloniemi ◽  
Sanna Herranen ◽  
Anneli Eteläpelto
Keyword(s):  
Qualitative Content Analysis ◽  
Leadership Coaching ◽  
Content Type ◽  
Current State ◽  
Before And After ◽  
State Of Affairs ◽  
Practical Implications ◽  
A Current

Purpose Although there has been an increase in workplace studies on professional agency, few of these have examined the role of emotions in the enactment of agency at work. To date, professional agency has been mainly conceptualised as a goal-oriented, rational activity aimed at influencing a current state of affairs. Challenged by this, this study aims to elaborate the nature and quality of emotions and how they might be connected to the enactment of professional agency. Design/methodology/approach Data are collected in the context of a leadership coaching programme that aimed to promote the leaders’ professional agency over the course of a year. The participants (11 middle-management leaders working in university and hospital contexts) were interviewed before and after the programme, and the data were analysed using qualitative content analysis. Findings Findings showed that emotions played an important role in the leaders’ enactment of professional agency, as it pertained to their work and to their professional identity. The study suggests that enacting professional agency is by no means a matter of purely rational actions. Practical implications The study suggests that emotional agency can be learned and enhanced through group-based interventions reflecting on and processing one’s own professional roles and work. Originality/value As a theoretical conclusion, the study argues that professional agency should be reconceptualised in such a way as to acknowledge the importance of emotions (one’s own and those of one’s fellow workers) in practising agency within organisational contexts.

Deposition of epitaxial transition metal carbide films and superlattices by simultaneous direct current metal magnetron sputtering and C60 evaporation

2001 ◽  
Vol 16 (3) ◽  
pp. 633-643 ◽  
Author(s):  
H. Högberg ◽  
J. Birch ◽  
M. P. Johansson ◽  
L. Hultman ◽  
U. Jansson
Keyword(s):  
Epitaxial Growth ◽  
Deposition Process ◽  
Growth Conditions ◽  
Growth Behavior ◽  
Transition Metal Carbide ◽  
Structural Quality ◽  
Metal Carbide ◽  
General Observation ◽  
Better Than

Thin epitaxial TiC and VC films and superlattices have been deposited on MgO(001) by simultaneous sputtering of the metals and evaporation of C60. It was found that epitaxial growth conditions for TiC could be maintained down to a temperature of 100 °C, while the epitaxial growth of VC required 200 °C. Epitaxial VC films were completely relaxed at all growth temperatures, while a change from a relaxed to a strained growth behavior was observed for TiC films. The structural quality of the TiC films was better than for the VC films. A general observation was that a plasma-assisted deposition process yields films with a higher quality and allows epitaxial growth at lower temperatures than for a pure coevaporation process.

Magnetic Anisotropy of Strained La0.7Sr0.3MnO3 Thin Films Studied by MOKE

2001 ◽  
Vol 690 ◽  
Author(s):  
M. Koubaa ◽  
A.M. Haghiri-Gosnet ◽  
P. Lecoeur ◽  
W. Prellier ◽  
B. Mercey
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Scaling Law ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Growth Conditions ◽  
Structural Quality ◽  
Lattice Strains ◽  
Stress States

ABSTRACTThe effects of the growth conditions and the lattice strains of pulsed laser deposited (PLD) La0.7Sr0.3MnO3 (LSMO) thin films upon the magnetic behavior have been studied using magneto-optical Kerr effect (MOKE) at room temperature. First, the structural quality of the films was investigated by XRD and the surface morphology was studied using AFM. It is shown that both surface morphology and crystallinity are optimized when the target-to-substrate distance and the oxygen pressure are chosen in agreement with a PD3 scaling law. Secondly, hysteresis loops have been recorded along the [100], [110] and [001] directions and the easy directions of magnetization have been determined for both stress states, i.e. tension on SrTiO3 and compression on LaAlO3. In tensile films, the whole plane is found to be easy, whereas, in compressive films, the easy axis should be an intermediate direction between the film's plane and its normal. Moreover, tensile films deposited under optimized growth conditions exhibit the largest anisotropy coefficient (K1eff = -6.9×105 erg/cm3).

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