• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.461-467
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• 2011

The valence band maximum and the conduction band miminum of GaAs, GaSb, InAs, and InSb (constituent binaries of the quaternaty alloy $Ga_xIn_{1-x}Sb_yAs_{1-y}$) are calculated by using TB analytical approach method. The band alignment types of their heterojunctions are determined directly from their relative position of band edges (VBM and CBM). For example, the GaAs/InAs, GaAs/InSb, and GaSb/InSb are in a type-I, the GaAs/GaSb in a type-II, and the GaSb/InAs and InSb/InAs in a type-III, respectively. The composition dependent VBM and CBM for the $Ga_xIn_{1-x}Sb_yAs_{1-y}$ alloy are obtained by using the univeral tight binding method. For the alloyed heterojunctions, the band alignments can be controlled by changing the composition which induce a band type transition. For the alloy $Ga_xIn_{1-x}Sb_yAs_{1-y}$ lattice mathced to GaSb, the type-II band alignment in the region of $x{\leq}0.15$ is changed to the type-III in the region of $x{\geq}0.81$. On the other hand, the alloy $Ga_xIn_{1-x}Sb_yAs_{1-y}$ lattice mathced to InAs has the type-II band alignment in the region of $x{\leq}0.15$ and the type-III band alignment in the region of $x{\geq}0.81$, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.1
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• pp.33-37
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• 2008

The effects of Cu and Sb on the microstructure and mechanical properties of Sn-Sb-Cu-Ni-Cd whitemetal were investigated. Any compound phase was not observed in the whitemetal with 0.05 wt% Cu, while as the Cu content was increased, star- or needle-like $Cu_6Sn_5$ phases were found. The tensile strength gradually increased with Cu up to 5 % and then remained almost constant with Cu content above 5 %, while the hardness continuously increased with Cu content because of the increased hard $Cu_6Sn_5$ phases. As the Sb content increased, SbSn cuboids were present as well as $Cu_6Sn_5$. The tensile steength and hardness continuously increased and the elongation decreased with Sb content.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.6
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• pp.225-231
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• 2016

The valence band maximum (VBM) and conduction band minimum (CBM) of Al-doped GaInAsSb alloys substrated on GaSb are calculated by using an analytic approximation based on the tight binding method. The relative positions of the VBM and CBM between Al-GaInASSb and GaSb determine band alignement type, valence band offset (VBO) and conductin band offset (CBO) for the heterojunctions. In this study, aluminium doping is assumed to be substituted in the cation site and limited up to 20 % because it can easily oxidize and degrade materials. It is found that the Al-doped alloys exhibit type-II band alignments over the entire composition range and make the band gaps increase, whereas the VBO and CBO decrease. The decreasing rate of VBO is higher than that of CBO, which implies the Al components play a decisive role in controlling electrons at the interface. The Al-dopled GaInAsSb alloy has a direct band gap induced by $E({\Gamma})$ with a considerable distance from the E(L) and E(X), however, $E({\Gamma})$ approaches to E(L) and E(X) in the high Sb concentration (Sb > 0.7-0.8) which might affect the electron mobility and degrade the optical quality.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.167-167
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• 2010

반도체는 도핑하지 않으면 대부분 n형을 나타내는 것에 반하여 GaSb는 p형을 보이는 반도체로서, 그 근원은 명확하게 규명되어 있지 않은 상태이다. GaSb의 p형 불순물인 Be은 Ga과 치환 ([$Be_{Ga}$])되므로, p형 전도의 근원으로 추정되는 잔존결함인 [$Ga_{Sb}$]와 그 복합체인 [$Ga_{Sb}-Sb_{Ga}$]와 높은 상관관계를 가질 것으로 예측된다. 본 연구에서는 Be을 도핑한 GaSb:Be 에피층을 MBE 방법으로 성장하여, PL 스펙트럼과 Hall 효과 분석을 통하여 p형 전도의 근원을 조사하였다. 도핑하지 않은 u-GaSb는 DA (deep acceptor)와 함께 A 준위를 나타낸 반면, p-GaSb:Be의 PL 스펙트럼은 Be 도핑농도가 증가함에 따라 FWHM가 줄어들면서 점차 높은 에너지 영역으로 변위하지만 농도가 가장 높은 시료에서는 PL의 FWHM가 증가하면서 에너지는 감소함이 관측되었는데, 이것은 A 피크와 Sb 관련 피크가 경쟁적으로 중첩되어 나타난 현상으로 분석된다. Hall 효과 결과는 유효 전하밀도의 증가에 따라 이동도는 감소하는 전형적인 의존성을 나타내었으며, u-GaSb의 Hall 이동도가 p-GaSb:Be의 값보다 작은 것은 u-GaSb에 잔존하는 DA에 의한 산란 때문으로 해석된다. Gaussian 형태로 분해하여 얻은 A ([$Ga_{Sb}$])와 DA ([$Ga_{Sb}-Sb_{Ga}$]) 및 Be 관련 피크로부터 특정 도핑농도 ($1.2{\times}10^{17}cm^{-3}$)의 시료를 제외한 모든 p-GaSb:Be에는 A 피크가 중첩되고 A와 Be 준위 중간에 Be과의 복합체인 중간상태(intermediate state)인 [$Be^*$]가 존재함이 관측되었는데, 특정 도핑농도에서는 [$Be_{Ga}$]이 우세하지만 더 이상 농도가 증가하면 [$Be_{Ga}$] 준위의 강도는 오히려 감소함을 관측할 수 있었다. 이것은 적정 이상의 Be을 도핑할 경우, A ([$Be_{Ga}$])와 $Be^*([Be_{Ga}-Ga_Sb}])$가 형성 ($A[Ga_{Sb}]+Be{\rightarrow}Be^*[Be_{Ga}-Ga_{Sb}]+[Be_{Ga}]$)됨을 보여 주는 중요한 결과인 것으로 분석된다. A, [Be], [$Be^*$] PL 피크 에너지는 각각 779, 787, 794 meV (오차범위 ${\pm}3\;meV$)이고, [$Be_{Ga}$]의 활성화 에너지는 ($23{\pm}3\;meV$) (20 K)임을 밝혔다.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.647-650
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• 1996

Fifteen sheep were used in a trial which compared the feeding value of whole barley gain and cottonseed cake as supplements to a basal diet of leaves of fourwing saltbush (Atriplex canescens). Diet SB contained 700 g (air-dry matter) of saltbush alone, diet SB + BG contained 700 g SB with 400 g whole barley grain and diet SB + CS contained 700 g SB with 400 g cottonseed cake. The digestibility of the dry matter of diets SB (69%) and SB + CS (70%) were lower (p < 0.001) than of diet SB + BG (76%). Sheep offered SB alone daily lost 80g whereas those fed the other diets gained 11 g (SB + CS) or 17 g (SB + BG) per day. Daily water consumption of the sheep offered the three diets was similar (p > 0.05), but their water consumption was higher (p < 0.001) than that of sheep offered daily 700 g wheat straw and 200 g barley grain. The results indicate that, at the levels of feeding used, barley grain and cottonseed cake had similar value as supplements to fourwing saltbush harvested in summer. The addition of the supplement allowed the sheep to gain some live weight. However, the presence of saltbush leaves in the diet resulted in higher water intakes by the sheep.

• Resources Recycling
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• v.21 no.4
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• pp.53-59
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• 2012

In this study, behaviors of removing Sb and Pb by oxidation of molten Bi-Pb-Sb alloy which is a by-product of non-ferrous smelting process was investigated. The molten alloy was oxidized at 1173 K by bubbling $N_2+O_2$ gas through a submerged nozzle. The Sb was removed and recovered as mixed phase of $Sb_2O_3$ and metal Sb. In the case of bubbling $N_2+O_2$ gas into molten Bi-Pb alloy at 923 K, Pb was oxidized and removed to slag. But Bi could not be refined due to simultaneous oxidization of Bi with Pb.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.223-223
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• 2010

InSb 물질은 다른 III-V족 물질들과 비교해서 bandgap이 낮고 전자 이동도가 높아, 소자 구현 시 낮은 전압으로도 고속 동작 특성을 제어할 수 있다는 장점이 있다. 그러나 Si, GaAs 또는 InP 등 쉽게 구할 수 있는 기판과 격자 부정합이 커서 상기 기판에 성장시 많은 defect가 존재하는 단점이 있다. 그러므로 이를 상기 기판에 성장하는데 meta-morphic이라 불리는 성장 기술이 요구되는 어려움이 있다. 본 발표에서 Semi-insulating GaAs 기판위에 고품질의 InSb 박막을 성장하기 위해 grading buffer technique을 도입하며 이에 대한 여러 가지 비교실험과 함께 최적의 성장 방법과 기술에 대해 논의 한다. GaAs와 InSb 물질사이의 bandgap과 격자 부정합을 고려하여 AlSb 물질을 먼저 성장하면서 동시에 InxAl1-xSb로 변화를 주어 InSb 박막이 성장되도록 하였다. ($x=0{\rightarrow}1$). 성장 온도 변화 및 In과 Al의 조성비에 변화를 주어 grading 기법으로 성장하였고 상기 grading buffer위에 InSb 박막을 0.65um 성장하였다. $10um{\times}10um$ AFM 측정결과 2.2nm 정도의 표면 거칠기를 가지며 상온에서의 전자 이동도는 약 46, 300 cm2/Vs 이고 sheet electron density는 9.47(e11) /cm2의 결과를 확인하였다. 실험결과 InSb 박막을 올리는데 있어 가장 고려할 사항인 GaAs 기판과 InSb 박막 사이에 존재하는 격자 부정합을 어떻게 해결하는가에 대해서, 기존의 여러가지 방법과 비교해서 grading buffer 기술이 유효하다는 것을 증명하였다.

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.1000-1005
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• 1999

To investigate the effects of V and Sb on the recrystallization of Zr-0.8Sn alloy, the microstructure of heat-treated specimens was observed by optical microscope, SEM, and TEM. Microhardness tests were also carried out for the annealed specimens. From microstructural studies, the V or Sb additions were found to delay recrystallization process as well as grain growth. Especially, Sb was more effective in delaying the recrystallization. This delay of recrystallization and grain growth by V or Sb additions may be due to the interference in the movement of dislocation and crystal interface by V or Sb precipitates.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.5
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• pp.411-414
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• 2008

The germanium films were deposited by metal organic chemical vapor deposition using $Ge(allyl)_4$ precursors on TiAlN substrates. Deposition of germanium films was only possible with a presence of $Sb(iPr)_3$, which means that $Sb(iPr)_3$ takes a catalytic role by a thermal decomposition of $Sb(iPr)_3$ for Ge film deposition. Also, as Sb bubbler temperature increases, deposition rate of the Ge films increases at a substrate temperature of $370^{\circ}C$. The GeTe thin films were fabricated by MOCVD with $Te(tBu)_2$ on Ge thin film. The GeTe films were grown by the tellurium deposition at $230-250^{\circ}C$ on Ge films deposited on TiAlN electrode in the presence of Sb at $370^{\circ}C$. The GeTe film growth on Ge films depends on the both the tellurium deposition temperature and deposition time. Also, using $Sb(iPr)_3$ precursor, GeSbTe films with hexagonal structures were fabricated on GeTe thin films. GeSbTe films were deposited in trench structure with 200 nm*120 nm small size.

• Imaging Science in Dentistry
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• v.48 no.4
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• pp.277-281
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• 2018

Purpose: This study was performed to investigate the relationship between sleep bruxism(SB) and pulpal calcifications in young women. Materials and Methods: A total of 100 female participants between 20 and 31 years of age who were referred to our radiology clinic for a dental check-up, including 59 SB and 41 non-SB patients, were sampled for the analysis. SB was diagnosed based on the American Academy of Sleep Medicine criteria. All teeth were evaluated on digital panoramic radiographs to detect pulpal calcifications, except third molars, teeth with root canal treatment, and teeth with root resorption. Binary logistic regression analysis was used to determine the risk factors for pulpal calcifications. The Spearman correlation coefficient was applied and the Pearson chi-square test was used for categorical variables. To test intra-examiner reproducibility, Cohen kappa analysis was applied. P values <.05 were considered to indicate statistical significance. Results: A total of 2800 teeth were evaluated (1652 teeth from SB patients and 1148 from non-SB patients), and 61% of patients had at least 1 dental pulpal calcification. No statistically significant relationship was found between SB and pulpal calcifications (P>0.05). In SB patients, the total number of pulpal calcifications was 129, while in non-SB patients, it was 84. Binary logistic analysis showed that SB was not a risk factor for the presence of pulpal calcifications(odds ratio, 1.19; 95% CI, 0.52-2.69, P>.05). Conclusion: No relationship was found between SB and pulpal calcifications.