열처리 후 플럭스 사파이어와 천연 사파이어의 비교 분석

김기인,안용길,서진교,박종완,Kim, Ki-In,Ahn, Yong-Kil,Seo, Jin-Gyo,Park, Jong-Wan 한국결정성장학회 2009 한국결정성장학회지 Vol.19 No.3

산업용 뿐만 아니라 보석용으로 가치가 있는 사파이어는 매우 다양한 방법으로 합성 사파이어를 만들어 왔다. 그 중 천연 사파이어와 매우 유사하며 보석용으로 가치가 높은 Chatham사의 플럭스 사파이어를 사용하여 천연 사파이어와 비교하였다. 먼저 WD-XRF(Wavelength dispersive x-ray fluorescence spectrometer)를 사용하여 천연과 합성의 화학 조성을 비교하였다. 천연 사파이어는 화학 조성이 매우 다양하였으나 플럭스 사파이어는 천연과 유사한 화학 성분과 특히 Mo, Pt, Pb 미량원소가 검출되었다. Pt는 플럭스 사파이어라는 결정적인 증거가 된다. 다음으로 $1300^{\circ}C$와 $1500^{\circ}C$의 고온에서 열처리를 한 후 자외선-가시광선 분광광도계(UV-VIS Spectrophotometer)를 사용하여 분광학적 특성을 조사함으로써 천연 사파이어는 $Cr^{3+}$와 관련된 약 690nm의 형광과 관련된 흡수 피크의 변화를 관찰할 수 있었고 플럭스 사파이어는 $Cr^{3+}$와 관련된 약 690nm의 피크와 376nm, 388nm의 $Fe^{3+}$의 흡수 피크가 변화함을 볼 수 있었다. 고온 열처리에 의해 플럭스 사파이어의 흡수 피크의 변화가 천연 사파이어의 흡수 피크의 변화보다 더 큰 것을 알 수 있었다 화학조성 및 분광분석 실험을 통하여 천연 사파이어와 flux 합성 사파이어의 특성을 비교 분석하였다. Various fabrication methods have been used to synthesize sapphire which has qualities of jewelry well beyond the industrial class. Among them, the flux sapphire of Chatham Company which has as high value as jewelry was selected in order to compare natural and synthetic sapphire. First, the WD-XRF (Wavelength dispersive x-ray fluorescence spectrometer) was used to analyze the chemical composition of natural and synthetic sapphire. Although natural sapphire had very diverse chemical compositions, flux sapphire had small quantities of Mo, Pt and Pb elements in addition to the similar chemical ingredients to natural one. Pt is decisive proof of flux sapphire. Next, by investigating spectroscopic characteristics using UV-VIS Spectrophotometer after heat treatment at high temperatures of $1300^{\circ}C$ and $1500^{\circ}C$, the variation of 690 nm absorbance related to $Cr^{3+}$ was detected in the natural sapphire while those of the 690 nm absorbance (related to $Cr^{3+}$) as well as absorbance of 376 nm and 388 nm ($Fe^{3+}$) were seen in the flux sapphire. It was found that the difference in the absorbance variation of flux sapphire is greater than that of natural sapphire after heat treatment. The chemical composition and spectrum analysis were utilized to compare the natural sapphire and the flux synthetic sapphire.

사파이어 기판방향에 따른 GaN 박막의 표면탄성파 특성에 대한 이론적 계산

임근환,김영진,최국현,김범석,김형준,김수길,신영화 한국세라믹학회 2003 한국세라믹학회지 Vol.40 No.6

GaN/사파이어 박막구조는 높은 SAW속도로 인해 고주파 소자로 이용될 가능성이 있다. 일반적으로, GaN 박막은 사파이어의 c, a, 그리고 r-면에 성장한다. 본 연구에서는 사파이어의 기판과 GaN 박막사이의 결정학적 관계에 따라 GaN/사파이어 구조의 파동 방정식을 계산하였다. 각각의 면에서, GaN의 kH와 사파이어의 기판방향에 따라 전단속도가 변화하였다. 그 결과 r-면의 경우 전기기계결합계수가 우수했다. 즉, 재료의 탄성상수와 전기기계결합계수는 기판의 cut 방향과 방향성에 좌우된다. 또한, GaN/r-면 사파이어는 전기기계결합계수가 우수하므로 고주파수 대역 SAW 소자 응용에 보다 더 좋을 것이다. The GaN/sapphire layered structure is a potential candidate for high frequency devices due to high acoustic velocity of sapphire. Generally, the GaN thin films are epitaxially grown on c, a, and r-plane sapphire substrates. In this study, wave equations of GaN/sapphire structure were calculated according to crystallographic relationship between GaN layer and sapphire substrate. On each plane, the shear velocity was changed by the kH of GaN layer and propagation direction on sapphire substrate. We found electromechanical coupling constant of r-plane was better than the others. As a result, elastic stiffness and electromechanical coupling constant of materials are affected by a cut and an orientation of substrate. GaN/r-plane sapphire structure is more advantageous for high frequency SAW devices.

사파이어의 『푸쉬』와 리 다니엘즈의 <프레셔스 : 사파이어의 소설 『푸쉬』의 각색> 비교

신진범(Synn, Jin-beom) 건국대학교 스토리앤이미지텔링연구소 2017 스토리&이미지텔링 Vol.13 No.-

이 논문에서는 소설과 영화라는 두 매체의 다른 재현 방식에 강조점을 두면서 사파이어의 『푸쉬』와 리 다니엘즈의 <프레셔스: 사파이어의 소설 『푸쉬』의 각색> 을 비교하였다. 리 다니엘즈는 오렌지색을 상징으로 사용하며 모녀 관계의 회복에 초점을 맞춘 반면, 사파이어는 저널 쓰기 치료와 대안학교 학생들이 함께 쓰고 엮은 책을 강조한다. 소설에는 영화로 옮기기에는 많은 잔인한 부분들이 있기에 다니엘즈는 비참한 근친상간 부분들을 축소시키고 높은 자존감과 사랑을 줄 수 있는 마음을 가지지 못한, 가해자이자 희생자인 프레셔스의 어머니를 묘사하기 위해 프레셔스와 어머니 사이의 반목의 분량을 더 늘렸다. 사파이어와 다니엘즈는 프레셔스의 현실감과 희망을 고무시키기 위해 모두 말콤 X, 앨리스 워커 등과 같은 역사적, 문학적 인물을 사용한다. 하지만 이런 등장인물에서도 미묘한 차이가 있다. 사파이어의 인물들은 밀접하게 문학적인 인물들과 연결이 된 반면 다니엘즈는 정치적인 인물들을 강조한다. 작가와 감독 모두의 장점을 고려할 때, 두 작품들은 등장인물들 사이에서의 프레셔스의 잠재력과 조화 그리고 상호관련성을 보여준다. 비록 두 매체의 접근방식이 서로 다르지만, 두 작품 모두 프레셔스의 희망, 회복, 그리고 생존을 향한 여정에 초점을 맞추고 있다. This article deals with a comparison of Sapphire’s novel, Push and Lee Daniels’ movie adaptation, Precious: Based on the Novel Push by Sapphire. This article gives emphases on the different representations of two media: novel and film. Sapphire lays emphases on the effect of journal writing cure and a compiled book students of an alternative school co-author; while Lee Daniels focuses on the reconciliation of mother-daughter relationship by using the symbol of orange color. The novel has many cruel parts to be made into a film, for that reason, Daniels shortens the miserable incest scenes and lengthens the struggle of Precious and her mother, Mary, to exhibit that the mother is both an inflictor and a victim who doesn’t have high self-esteem and a love-giving heart. Both Sapphire and Daniels use the historic and literary figures like Malcolm X, Alice Walker and others to inspire Precious’ sense of reality and hope. There exists, however, a subtle difference in these figures: Sapphire’s are closely related with literary figures, while Daniels emphasizes political figures. Considering their own strengths, both works show Precious’ potentials and the harmony and interrelatedness among the characters. Though the approaches of these two are different, they focus on Precious’ journey into hope, recovery, and survival.

Fabrication of high performance copper-resin lapping plate for sapphire: A combined 2-body and 3-body diamond abrasive wear on sapphire

Pyun, Hae-Jung,Purushothaman, Muthukrishnan,Cho, Byoung-Jun,Lee, Jung-Hwan,Park, Jin-Goo Elsevier 2018 Tribology international Vol.120 No.-

<P><B>Abstract</B></P> <P>In this study, a sapphire lapping plate was fabricated using a unique blend of copper (Cu) metal particles and resin to overcome the drawbacks of traditional iron (Fe) and Cu plate lapping. An optimum Cu-resin ratio was found by evaluating the MRR, surface roughness of the lapped sapphire and the hardness of the Cu-resin plate. Cu-resin plates with various groove patterns were prepared, and a suitable pattern was found with respect to MRR and surface roughness of processed sapphire. A new concept of a temporary 2-body and permanent 3-body diamond abrasion mechanism was proposed for the sapphire lapping process using the interface of the Cu-resin plate. The proposed mechanism on sapphire lapping may support future developments in this field.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This is the first systematic work for the fabrication of copper (Cu)-resin lapping plate for the sapphire substrate. </LI> <LI> The interface, the micro gap between the Cu particle and resin in the fabricated lapping plate, determines whether the lapping is 3 body diamond abrasion or temporary 2 body abrasion. </LI> <LI> Higher material removal (MRR) and lower surface roughness of sapphire is achieved by using Cu-resin lapping plate when compared to pure metal plate lapping. </LI> <LI> COO (cost of ownership) is less with high throughput upon sapphire lapping process by developed Cu-resin plate. </LI> </UL> </P>

국내산 블랙 사파이어와 다른 품종 포도의 이화학적 특성 및 영양성분

박서연(Seo-Yeon Park),강내경(Nae-Kyong Kang),황명진(Myung-Jin Hwang),김은희(Eun-Hee Kim),김상미(Sang-Mi Kim),이종헌(Jong-Hun Lee),이상훈(Sang-Hoon Lee),남진식(Jin-Sik Nam) 한국식품영양과학회 2021 한국식품영양과학회지 Vol.50 No.9

본 연구에서는 국내에서 재배한 블랙 사파이어, 캠벨 얼리, 머루, 거봉의 이화학적 특성 및 영양성분을 조사하여 분석하였다. L-value는 블랙 사파이어, a-value는 머루가 가장 높았으며, b-value는 명도와 유사한 경향으로 나타났다. 가용성 고형분은 머루가 19.67°Brix로 가장 높았으며, pH는 블랙 사파이어가 3.56으로 가장 높았다. 산도는 거봉이 0.91%로 가장 높았다. 포도의 수분 함량은 79.75~87.44%의 범위로 품종별로 유의적인 차이가 있었다(P<0.05). 식이섬유 함량을 조사한 결과로 포도의 품종 중 머루가 가장 높았으며 캠벨 얼리, 블랙 사파이어, 거봉 순으로 확인되었다. 포도의 주요한 무기질은 칼륨이었으며 머루(2,718.86 mg/kg), 거봉(2,078.55 mg/kg), 블랙 사파이어(1,901.34 mg/kg), 캠벨 얼리(1,891.79 mg/kg) 순으로 함량이 나타났다. 비타민 B₁은 거봉이 2.11 μg/100 g이 가장 높았으며, 비타민 B₂는 캠벨 얼리가 36.10 μg/100 g으로 가장 높았다. 비타민 C의 함량은 거봉이 0.54 mg/100 g으로 가장 높았다. 총 지방산의 함량은 머루가 357.80 mg/100 g으로 가장 높았다. 모든 품종의 주요한 포화 지방산으로는 palmitic acid(C16:0)로 확인되었으며, 검출된 불포화 지방산 중 주된 성분으로는 linoleic acid(C18:2, n-6)로 조사되었다. 과당(fructose)과 포도당(glucose)은 모든 품종에서 검출되었다. 이러한 결과는 품종에 따른 포도를 이용하는데 필요한 기초자료로 활용할 수 있을 것으로 판단된다. In this study, the physicochemical properties and nutrient components of grapes including sweet sapphire, campbell early, Muscat Bailey A (MBA), and kyoho that are grown in Korea were investigated and analyzed. Considering color, sweet sapphire was the highest in terms of its L-value, and the MBA was the highest in terms of its a-value, and the b-values showed a similar trend to the lightness. The soluble solid content was the highest with 19.67°Brix in the MBA and the highest pH was 3.56 in the sweet sapphire. The acidity of kyoho was the highest at 0.91%. The moisture content of grapes ranged from 79.75 to 87.44%. An analysis of the dietary fiber content showed that MBA was the highest followed by campbell early, sweet sapphire, and kyoho. The main mineral in the grapes was potassium, and the content was obtained in the decreasing order of MBA, kyoho, sweet sapphire, and campbell early. The vitamin B1 content was the highest at 2.11 μg/100 g in kyoho, and vitamin B2 was the highest in campbell early at 36.10 μg/100 g. The content of vitamin C was the highest in kyoho (0.54 mg/100 g). The content of total fatty acids was highest in MBA at 357.80 mg/100 g. Palmitic acid was identified as the major saturated fatty acid of all varieties, and linoleic acid was identified as the main component of unsaturated fatty acids. Fructose and glucose were detected in all cultivars. These results can be used as the basic data needed for the proper utilization of each variety of grapes.

Study of Several Silica Properties Influence on Sapphire CMP

Wang, Haibo,Zhang, Zhongxiang,Lu, Shibin The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

Colloid silica using as abrasive for polishing sapphire has been extensively studied, which mechanism has also been deeply discussed. However, by the requirement of application enlargement and cost reduction, some new problems appear such as silica service life time, particle diameter mixing, etc. In this paper, several influences of colloid silica usage on sapphire CMP are examined. Results show particle diameter and concentration, pH value, service life time, particle diameter mixing heavily influence removal rate. Further analysis discloses there are two main effect aspects which are quantity of hydroxyl group, contact area for abrasive density stacking between abrasive and sapphire. Based on the discussions, a dynamic process of sapphire polishing is proposed.

활성화 이온빔 처리된 Sapphire기판 위에 성장시킨 MOCVD-GaN 박막의 격자변형량 측정

김현정,김긍호,Kim, Hyun-Jung,Kim, Gyeung-Ho 한국현미경학회 2000 Applied microscopy Vol.30 No.4

사파이어 기판을 이용한 GaN 박막성장에서 완충층의 사용과 기판의 질화처리는 GaN 박막 내의 격자결함을 줄이는 가장 보편적인 방법이다. GaN박막의 초기 핵생성과 성장 거동을 향상시키기 위한 새로운 방법으로 사파이어 표면을 질소 활성화 이온빔으로 처리하는 방법이 시도되었다. 활성화 이온빔 처리의 결과 약 10nm두께의 비정질 $AlO_xN_y$ 층이 형성되었으며 GaN의 성장온도에서 부분적으로 결정화되어 계면 부위에 고립된 비정질 영역으로 존재하였다. 계면에 존재하는 비정질 층은 기판과 박막사이에서 발생하는 열응력을 효과적으로 감소시키는 역할이 가능하며 이를 확인하기 위하여 활성화 이온빔 처리에 의한 GaN박막 내의 격자변형량 차이를 비교하였다. GaN박막에서 얻어진 $[\bar{2}201]$ 정대축고차 Laue도형을 전산모사 도형과 비교하여 격자변형량을 측정하였다. 본 연구의 결과 활성화 이온빔 처리를 하지 않은 기판 위에 성장시킨 GaN박막의 격자변형량은 처리한 경우에 비해 6배 이상 높은 값을 가졌으며 따라서 활성화 이온빔 처리에 의해 GaN박막의 열응력은 크게 감소함을 확인하였다. Introduction of the buffer layer and the nitridation of a sapphire substrate were one of the most general methods employed for the reduction of lattice defects in GaN thin films Brown on sapphire by MOCVD. In an effort to improve the initial nucleation and growth condition of the GaN, reactive ion beam (RIB) of nitrogen treatment of the sapphire surface has been attempted. The 10 nm thick, amorphous $AlO_xN_y$ layer was formed by RIB and was partially crystallized alter the main growth of GaN at high temperature, leaving isolated amorphous regions at the interface. The beneficial effect of amorphous layer at interface in relieving the thermal stress between substrate and GaN film was examined by measuring the lattice strain value of the GaN film grown with and without the RIB treatment. Higher order Laue zone pattern (HOLZ) of $[\bar{2}201]$ zone axis was compared with simulated patterns and lattice strain was estimated It was confirmed that the great reduction of thermal strain was achieved by RIB process and the amount of thermal stress was 6 times higher in the GaN film grown by conventional method without the RIB treatment.

Study of Several Silica Properties Influence on Sapphire CMP

Haibo Wang,Zhongxiang Zhang,Shibin Lu 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

Colloid silica using as abrasive for polishing sapphire has been extensively studied, which mechanism has also been deeply discussed. However, by the requirement of application enlargement and cost reduction, some new problems appear such as silica service life time, particle diameter mixing, etc. In this paper, several influences of colloid silica usage on sapphire CMP are examined. Results show particle diameter and concentration, pH value, service life time, particle diameter mixing heavily influence removal rate. Further analysis discloses there are two main effect aspects which are quantity of hydroxyl group, contact area for abrasive density stacking between abrasive and sapphire. Based on the discussions, a dynamic process of sapphire polishing is proposed.

단결정 사파이어 광학소자의 ELID 경면연삭 가공 특성

곽재섭(Jae-Seob Kwak),김건희(Geon-Hee Kim),이용철(Yong-Chul Lee),오오모리 히토시(Hitoshi Ohmori),곽태수(Tae-Soo Kwak) Korean Society for Precision Engineering 2012 한국정밀공학회지 Vol.29 No.3

This study has been focused on application of ELID mirror-surface grinding technology for manufacturing single crystal optic sapphire. Single crystal sapphire is a superior material with optic properties of high performance as light transmission, thermal conductivity, hardness and so on. Mirror-surface machining technology is necessary to use sapphire as optic parts. The ELID grinding system has been set up for machining of the sapphire material. According to the ELID experimental results, it shows that the surface of sapphire can be eliminated by metal bonded wheel with micron abrasives and the surface roughness of 60nmRa can be gotten using grinding wheel of 2,000 mesh in 4.5um, depth of cut. In this study, the chemical experiments after ELID grinding also has been conducted to check chemical reaction between workpiece and grinding wheel on ELID grinding process. It shows that the chemical reaction has not happened as the results of the chemical experiments.

Feasibility for non-destructive discrimination of natural and beryllium-diffused sapphires using Raman spectroscopy

Chang, K.,Lee, S.,Park, J.,Chung, H. Pergamon Press ; Elsevier Science Ltd 2016 Talanta Vol.149 No.-

<P>Raman spectroscopy based non-destructive discrimination between natural and beryllium-diffused (Be diffused) sapphires has been attempted. The initial examination of Raman image acquired on a sapphire revealed that microscopic structural and compositional heterogeneity was apparent in the sample, so acquisition of spectra able to represent a whole body of sapphire rather than a localized area was necessary for a reliable discrimination. For this purpose, a wide area illumination (WAI) scheme (illumination area: 28.3 mm(2)) providing a large sampling volume was employed to collect representative Raman spectra of sapphires. Upon the diffusion of Be into a sapphire, the band shift originated from varied lattice structure by substitution of Be at cation sites was observed and utilized as a valuable spectral signature for the discrimination. In the domain of principal component (PC) scores, the groups of natural and Be-diffused sapphires were identifiable with minor overlapping and the cross validated discrimination error was 7.3% when k-Nearest Neighbor (k-NN) was used as a classifier. (C) 2015 Elsevier B.V. All rights reserved.</P>