• 한국정밀공학회지
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• 제23권8호
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• pp.72-79
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• 2006

We measured grating pitch standards using optical diffractometry and analyzed measurement uncertainty. Grating pitch standards have been used widely as a magnification standard for a scanning electron microscope (SEM) and a scanning probe microscope (SPM). Thus, to establish the meter-traceability in nano-metrology using SPM and SEM, it is important to certify grating pitch standards accurately. The optical diffractometer consists of two laser sources, argon ion laser (488 nm) and He-Cd laser (325 nm), optics to make an incident beam, a precision rotary table and a quadrant photo-diode to detect the position of diffraction beam. The precision rotary table incorporates a calibrated angle encoder, enabling the precise and accurate measurement of diffraction angle. Applying the measured diffraction angle to the grating equation, the mean pitch of grating specimen can be obtained very accurately. The pitch and orthogonality of two-dimensional grating pitch standards were measured, and the measurement uncertainty was analyzed according to the Guide to the Expression of Uncertainty in Measurement. The expanded uncertainties (k = 2) in pitch measurement were less than 0.015 nm and 0.03 nm for the specimen with the nominal pitch of 300 nm and 1000 nm. In the case of orthogonality measurement, the expanded uncertainties were less than $0.006^{\circ}$. In the pitch measurement, the main uncertainty source was the variation of measured pitch values according to the diffraction order. The measurement results show that the optical diffractometry can be used as an effective calibration tool for grating pitch standards.

• 한국세라믹학회지
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• 제22권2호
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• pp.44-50
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• 1985

The crystallization behavior of $K_2O-SiO_2$ glasses with added $TiO_2$ and the effect of $TiO_2$ on internal nuleation at temperature in the range of 875 to 121$0^{\circ}C$ have been investigated by means of X-ray diffractometry optical microscopy and scanning electron microscopy. The crystalline phase of these glasses identified by X-ray diffractometry is cristbalite. The scanning electron microspcopy reveals a two-phase layer of dendritic crystals and intersitial melt which grow from the surface at a constant rate, The observed crystallization rates are consistent with a diffusion-controlled mechanism. An equation relating viscosity and undercooling to growth rate is presented.

• 한국결정성장학회지
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• 제27권3호
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• pp.105-109
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• 2017

고주파 유도 가열 장치를 이용하여 승화법으로 성장된 AlN 단결정을 질소 분위기 하에서 $1200^{\circ}C$와 $1500^{\circ}C$에서 열처리하였다. 열처리 후 단결정 시편들의 표면을 광학현미경으로 관찰하였으며, DCXRD(Double crystal X-ray Diffractometry)를 이용하여 FWHM(Full width of half maximum) 값을 측정하여 결정성의 변화를 평가하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.854-857
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• 2006

The synthesis of ester type, banana-shaped, photo - crosslinkable mesogens is described. The reactive mesogens, derivatives of 1,3-phenylene bis{4-[4'- (alken-1-yloxy)-biphenyl-4-carboxylate]benzoate}s, were synthesized varying the length of alkyl end groups. The obtained monomers and polymers were characterized by FT/IR, NMR spectroscopy, DSC, polarized optical microscopy, and X-ray diffractometry.

• 한국세라믹학회지
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• 제18권4호
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• pp.219-228
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• 1981

To clarify influences of silicious raw materials on mineralogcal and petrological properties in clinkering process clay, shale, quartzite, sand and coal ash have been used as silicious raw materials. The tests on thermal properties, reactivity and burnability of raw mixtures which have different silicious raw materials respectively have been made by means of X-ray diffractometry, differential thermal analysis, optical microscopy and transmission electron microscopy. Limestone contains coarse crystalline grains which show 0.1-1.0mm and its decarbonation temperature is 86$0^{\circ}C$. Reaction temperatures among raw mixtures have been determined by X-ray diffractometry and their results are as follows; clay minerals under 1, 00$0^{\circ}C$, mica group, 100$0^{\circ}C$-110$0^{\circ}C$, feldspar group, 1, 10$0^{\circ}C$-1, 20$0^{\circ}C$ and quartz 1, 20$0^{\circ}C$-1, 30$0^{\circ}C$. Burnabilities of raw mixtures of different temperatures have been found that they mainly depend upon their mineral contents in silicious raw materials and their order is as follows; $clay\geq shale\gg quartzite \geq sand$.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.324-326
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• 2008

Novel X-shaped molecules containing perfluoroalkyl alkanes as a side chain have been synthesized and characterized. The properties of mesophases were investigated by a combination of differential scanning calorimetry (DSC), polarizing optical microscopy (POM), X-ray diffractometry (XRD) and electro-optical measurements.

• 한국결정성장학회지
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• 제34권2호
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• pp.61-65
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• 2024

HVPE(Hydride vapor phase epitaxy) 공법은 기체상의 원료를 사용하여 박막 또는 단결정을 제조하는 공법이다. 화학적 기상증착법의 원리를 적용하여 난용융성 또는 고융점의 물질의 단결정을 성장할 수 있는 공법으로서, 질화갈륨(GaN) 단결정을 얻을 수 있는 공법 중 하나이다. 최근 동 공법을 이용하여 질화알루미늄(AlN) 단결정을 성장하고자 하는 연구가 많이 수행되어져 왔으나, 아직은 좋은 결과를 얻지 못하고 있다. 본 연구에서는 AlN 단결정을 HVPE 공법으로 성장하고자 하였다. 성장 공정에서 질소를 운송가스(Carrior gas)로 사용하였으며, 질소(N2)의 양의 변화에 따른 성장 결과를 고찰하여 보았다. 질소의 양이 증가함에 따른 성장 결정의 변화 양상을 확인할 수 있었다. 성장된 AlN 단결정의 형상을 광학 현미경을 사용하여 관찰하였고, 이중결정 X선 회절 분석(DCXRD, Double crystal X-ray diffractometry)을 이용하여, AlN 결정의 생성을 확인함과 동시에 성장된 단결정의 결정성도 알아보았다.

• 한국표면공학회지
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• 제29권6호
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• pp.666-672
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• 1996

The optical property of CdTe thin film is important for applications such as the compound semiconductor type solar cells. CdTe films are prepared by RF sputtering at various substrate temperature between $25^{\circ}C$ and $300^{\circ}C$, then, annealed in argon gas environment at $400^{\circ}C$. The annealing process of the thin film caused variation in the film structure and the composition of films. The deformation of CdTe thin film was observed by X-ray diffractometry. After annealing, the grain size increased and the portion of the non-crystalline CdTe reduced. Futhermore, the structure of sputtered CdTe film grown at the substrate temperature more than $250^{\circ}C$ was enhanced in the (111) direction of zincblend structure. There was a discrepancy, in the spectroscopic ellipsometer spectrum, between the single crystal CdTe and the sputtered CdTe thin films, especially in the region over 3.2eV. An oxidation layer was found on the CdTe thin film by spectroscopic ellipsometry analysis.

• 한국자기학회지
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• 제4권1호
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• pp.32-38
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• 1994

조성변조 Co/Pt 다층박막의 자기적 성질 및 자기광학적 성질에 박막제조시 스퍼터링 Ar 가스 압력이 끼치는 영향을 조사하였다. 다층박막을 dc-magnetron 스퍼터링 방법으로 Ar 가스의 압 력을 2에서 30 mTorr 까지 변화시켜 가면서 제조한 후 주사 전자 현미경과 x-ray 회절실험을 이용한 미세구조의 분석과 보자력, 포화 자화량, Kerr 회전각, 반사도등의 자기 및 자기광학적 특성을 조사 하였다. Ar 가스의 압력이 10 mTorr 이하에서는 주상구조(colummar structure)가 형성되지 않다가 20 mTorr 부터 급격히 증가함이 관찰되었고, 이는 초격자 박막의 미세구조의 변화에 기인한다고 사 려된다. 또, 포화 자화량과 Kerr 회전각, 반사율등의 변화를 Ar 가스 압력의 변화에 따른 박막의 미 세구조와 연관지어서 설명하였다.

• 한국가시화정보학회지
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• 제22권1호
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• pp.18-27
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• 2024

A series of shock wave pulses with Mach number 2.2 of 100, 200, and 300 shocks were applied to lead sulfide (PbS) nanomaterials at intervals of 5 sec per shock pulse. To investigate the crystallographic, electronic, and magnetic phase stabilities, powder X-ray diffractometry (XRD), diffused reflectance spectroscopy (DRS), and vibrating-sample magnetometry (VSM) were employed. The material exhibited a rock salt structure (NaCl-type structure); XRD results indicated that material is monoclinic with space group C121 (5). Further, XRD results showed shifts due to lattice contraction and expansion when material was subjected to shock wave pulses, indicating stable material structure. Based on the data obtained, we believe that the PbS material is a good choice for high-pressure, high-temperature, and aerospace applications due to its superior shock resistance characteristics.