• 한국광물학회지
• /
• 제31권4호
• /
• pp.287-293
• /
• 2018

한반도 일부 토양에서 비정질 실리카($SiO_2$) 실트 입자들이 발견되었다. 토양 연마박편의 주사전자현미경에서 관찰된 비정질 $SiO_2$ 입자는 타원형이며, 1마이크론 이하의 극미세 공극들이 입자 내부에 집중 분포한다. 입자의 비정질성은 투과전자현미경 격자상 관찰과 전자회절로 확인하였다. 이 이질적인 실트 입자들의 풍성기원 가능성을 확인하기 위하여 중국 황토고원의 풍성퇴적물인 뢰스(loess) 내 $SiO_2$ 실트입자들을 조사하였으나 유사 입자를 확인하지 못하였다. 아직 기원이 명확하진 않지만, 식물규소체나 화산재 풍화물일 가능성이 있다. 토양환경에서 비정질 $SiO_2$ 실트 입자의 장거리 이동 광물먼지(황사) 추적자로서 가능성은 낮다.

• Transactions on Electrical and Electronic Materials
• /
• 제18권6호
• /
• pp.323-329
• /
• 2017

This reports the electrical behavior, bonding structure and Schottky contact of gallium-zinc-oxide (GZO) thin film annealed at $100{\sim}400^{\circ}C$. The mobility of GZO with high density of PL spectra and crystal structure was also increased because of the structural matching between GZO and Si substrate of a crystal structure. However, the GZO annealed at $200^{\circ}C$ with an amorphous structure had the highest mobility as a result of a band to band tunneling effect. The mobility of GZO treated at low annealing temperatures under $200^{\circ}C$ increased at the GZO with an amorphous structure, but that at high temperatures over $200^{\circ}C$ also increased when it was the GZO of a crystal structure. The mobility of GZO with a Schottky barrier (SB) was mostly increased because of the effect of surface currents as well as the additional internal potential difference.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2004년도 첨단 분리막 연구동향
• /
• pp.77-102
• /
• 2004

Carbon materials obtained from organic polymers are usually amorphous structure. The structure of carbon materials is not nearly as well defined as that of zeolite. Carbon are amorphous materials with comparatively wide pore size distribution as compared to the crystalline zeolites with monodisperse ultramicropore and micropore dimensions. (omitted)

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.368.1-368.1
• /
• 2014

We proposed amorphous GeSe-based ReRAM device of metal-insulator-metal (M-I-M) structure. The operation characteristics of memory device occured unipolar switching characteristics. By introducing the concepts of valance-alternation-pairs (VAPs) and chalcogen vacancies, the unipolar resistive switching operation had been explained. In addition, the current transport behavior were analyzed with space charge effect of VAPs, Schottky emission in metal/GeSe interface and P-F emission by GeSe bulk trap in mind. The GeSe ReRAM device of M-I-M structure indicated the stable memory switching characteristics. Furthermore, excellent stability, endurance and retention characteristics were also verified.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2011년도 추계학술발표대회
• /
• pp.36.2-36.2
• /
• 2011

Titanium and its alloys have been widely used for orthopedic implants because of their good biocompatibility. We have previously shown that the crystalline titania layers formed on the surface of titanium metal via anodic oxidation can induce apatite formation in simulated body fluid, whereas amorphous titania layers do not possess apatite-forming ability. In this study, hot water and heat treatments were applied to transform the titania layers from an amorphous structure into a crystalline structure after titanium metal had been anodized in acetic acid solution. The apatite-forming ability of titania layers subjected to the above treatments in simulated body fluid was investigated. The XRD and SEM results indicated hot water and/or heat treatment could greatly transform the crystal structure of titania layers from an amorphous structure into anatase, or a mixture of anatase and rutile.The abundance of Ti-OH groups formed by hot water treatment could contribute to apatite formation on the surface of titanium metals, and subsequent heat treatment would enhance the bond strength between the apatite layers and the titanium substrates. Thus, bioactive titanium metals could be prepared via anodic oxidation and subsequent hot water and heat treatment that would be suitable for applications under load-bearing conditions.

• 반도체디스플레이기술학회지
• /
• 제16권4호
• /
• pp.75-78
• /
• 2017

The $CO_2$ gas responsibility of $SnO_2$ thin films was researched with various annealing temperatures. $SnO_2$ was prepared on n-type Si substrate by RF magnetron sputtering system and annealed in a vacuum condition. The bonding structure of $SnO_2$ was changed from amorphous to crystal structure with increasing the annealing temperature, and the content of oxygen vacancy was researched the highest of the annealed at $60^{\circ}C$. The $SnO_2$ annealed at $60^{\circ}C$ had the characteristics of the highest capacitance. The special properties of $CO_2$ gas responsibility was found at the $SnO_2$ thin film annealed at $60^{\circ}C$ with amorphous structure because of the combination with the oxygen vacancies and $CO_2$ gases changed the resistivity. The amorphous structure enhanced the responsibility at the $SnO_2$ surface and the conductivity of $SnO_2$ thin film.

• Current Applied Physics
• /
• 제18권11호
• /
• pp.1289-1293
• /
• 2018

The influence of crystallization treatment on the structure, magnetic properties and magnetocaloric effect of $Gd_{71}Ni_{29}$ melt-spun ribbons has been investigated in detail. Annealing of the melt-spun samples at 610 K for 30 min, a majority phase with a $Fe_3C$-type orthorhombic structure (space group, Pnma) and a minority phase with a CrB-type orthorhombic structure (space group, Cmcm) were obtained in the amorphous matrix. The amorphous melt-spun ribbons undergo a second-order ferromagnetic to paramagnetic phase transition at 122 K. For the annealed samples, two magnetic phase transitions caused by amorphous matrix and $Gd_3Ni$ phases occur at 82 and 100 K, respectively. The maximum magnetic entropy change $(-{\Delta}S_M)^{max}$ is $9.0J/(kg{\cdot}K)$ (5T) at 122 K for the melt-spun ribbons. The values of $(-{\Delta}S_M)^{max}$ in annealed ribbons are 1.0 and $5.7J/(kg{\cdot}K)$, corresponding to the two adjacent magnetic transitions.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.322-325
• /
• 2009

Amorphous oxide semiconductors (AOSs) are expected as new channel materials in TFTs for largearea and/or flexible FPDs, and several prototype displays have been demonstrated in these five years since the first report of AOS TFT. In this paper, we review fundamental materials science of AOSs that have been clarified to date in connection with operation characteristics of AOS TFTs.

• 한국결정성장학회지
• /
• 제22권1호
• /
• pp.51-56
• /
• 2012

본 연구에서는 출발원료로 ${\sigma}$-VCo 금속간화합물과 $V_{50}Co_{50}$ 혼합분말을 각각 사용하여 기계적 합금화에 따른 비정질화 가능성을 조사하였다. X선 회절에 의해 얻어진 전구조인자 S(Q) 및 동경분포함수 RDF(r)의 결과로부터 볼밀링이 진행됨에 따라 비정질상의 구조적 특징이 분명히 관찰되었다. 120시간 MA 처리에 의하여 두 경우 모두에서 비정질상이 생성됨을 알 수 있었다. 60시간 동안 MA 처리한 $V_{50}Co_{50}$ 분말시료의 열분석 에서는 약 $600^{\circ}C$에 비정질상의 결정화에 의한 발열 peak가 관찰되었다. X선 회절법에 의해 얻어진 전구조인자 및 동경분포함수의 분석으로부터 MA 시간에 따라 출발 결정상은 비정질상의 특징적인 원자구조로 서서히 변화함을 알 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
• /
• pp.1308-1311
• /
• 2007

Leakage current produced by backside illumination on bottom-gated amorphous silicon thin film transistor has been investigated. The experimental results show that the leakage current of bottomgated structure is significantly dependent on the shape of amorphous silicon pattern. A proper design of amorphous silicon pattern has been suggested in viewpoint of reducing the leakage current as well as mass production.