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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Journal of Materials Research
Journal Basic Information
Journal DOI :
The Materials Research Society of Korea
Editor in Chief :
Volume & Issues
Volume 25, Issue 12 - Dec 2015
Volume 25, Issue 7 - Jul 2015
Volume 25, Issue 6 - Jun 2015
Volume 25, Issue 5 - May 2015
Volume 25, Issue 4 - Apr 2015
Volume 25, Issue 3 - Mar 2015
Volume 25, Issue 2 - Feb 2015
Volume 25, Issue 1 - Jan 2015
Selecting the target year
Dielectric and Ferroelectric Properties of Nb Doped BNT-Based Relaxor Ferroelectrics
Maqbool, Adnan ; Hussain, Ali ; Malik, Rizwan Ahmed ; Zaman, Arif ; Song, Tae Kwon ; Kim, Won-Jeong ; Kim, Myong-Ho ;
Korean Journal of Materials Research, volume 25, issue 7, 2015, Pages 317~321
DOI : 10.3740/MRSK.2015.25.7.317
The effects of Nb doping on the crystal structure, microstructure, and dielectric ferroelectric and piezoelectric properties of
, 0.01 and 0.02) ceramics have been investigated. X-ray diffraction patterns revealed that all ceramics have a pure perovskite structure with tetragonal symmetry. The grain size of the ceramics slightly decreased and a change in grain morphology from square to spherical shape was observed in the Nb-doped samples. The maximum dielectric constant temperature (
) increases with increasing amount of Nb; however, ferroelectric-relaxor transition temperature (
) and maximum dielectric constant (
) values decrease gradually. Nb addition disrupted the polarization hysteresis loops of the BNBT-SZ ceramics by leading a reduction in the remnant polarization coercive field and piezoelectric constant.
Optimization of Wear Behavior on Cenosphere -Aluminium Composite
Saravanan, V. ; Thyla, P.R. ; Balakrishnan, S.R. ;
Korean Journal of Materials Research, volume 25, issue 7, 2015, Pages 322~329
DOI : 10.3740/MRSK.2015.25.7.322
The magnitude of wear should be at a minimum for numerous automobile and aeronautical components. In the current work, composites were prepared by varying the cenosphere content using the conventional stir casting method. A uniform distribution of particles was ensured with the help of scanning electron microscopy (SEM). Three major parameters were chosen from various factors that affect the wear. A wear test was conducted with a pin-on-disc apparatus; the controlling parameters were volume percentages of reinforcement of 5, 10, 15, and 20%, applied loads of 9.8, 29.42, and 49.03 N, and sliding speeds of 1.26, 2.51, and 3.77 m/s. The design of the experiments (DOE) was performed by varying the different influencing parameters using the full factorial method. An analysis of variance (ANOVA) was used to analyze the effects of the parameters on the wear rate. Using regression analysis, a response curve was obtained based on the experimental results. The parameters in the resulting curve were optimized using the Genetic Algorithm (GA). The GA results were compared with those of an alternate efficient algorithm called Neural Networks (NNs).
Synthesis of Low-Thermal-Expansion Cordierite Ceramics Prepared from Pyrophyllite
Kim, Dong-Min ; Jung, Sook-In ; Lee, Hun-Chul ; Lee, Sang-Jin ;
Korean Journal of Materials Research, volume 25, issue 7, 2015, Pages 330~335
DOI : 10.3740/MRSK.2015.25.7.330
A low thermal expansion ceramic, cordierite (
), was synthesized using pyrophyllite. Pyrophyllite usually consists of
, which are the main components of cordierite.
were added in various amounts to pyrophyllite and fired for synthesis and sintering.
-cordierite crystallized from
with mixing of 20 wt%
and 1.7 wt%
, and un-reacted cristobalite was also detected with the cordierite. As the temperature was increased to
, the cordierite yield was gradually increased. Powder compacts of the synthesized cordierite were sintered between
; the sintered samples showed a low thermal expansion coefficient of
and typical sintering behavior. It is anticipated that it will be possible to synthesize cordierite ceramics on a mass production scale using the mineral pyrophyllite.
Effects of Firing Ambient on Rear Metallization for Silicon Solar Cells
Park, Sungeun ; Kim, Young Do ; Park, Hyomin ; Kang, Yoonmook ; Lee, Hae-Seok ; Kim, Donghwan ;
Korean Journal of Materials Research, volume 25, issue 7, 2015, Pages 336~340
DOI : 10.3740/MRSK.2015.25.7.336
For rear metallization with Al paste, Al back contacts require good passivation, high reflectance, and a processing temperature window compatible with the front metal. In this paper, the effect of the firing ambient during the metallization process on the formation of Al rear metal was investigated. We chose three different gases as ambient gases during the firing process. Using SEM, we observed the formation of a back surface field in
, and Air ambients. To determine the effect of the ambient on Voc, the suns-Voc tool was used. In this study, we described the mechanism of burn-out of organic materials in Al paste during the firing process. The oxygen ambient plays an important role in the burn-out process. We calculated the efficiency with obtained the back surface recombination velocities using PC1D simulation. It was found that the presence of oxygen during the firing process influenced the uniform back surface field because the organic materials in the Al paste were efficiently burned out during heating. The optimized temperature with oxygen flow shows an absolute efficiency of 19.1% at PC1D simulation.
Catalyst-Free and Large-Area Deposition of Graphitic Carbon Films on Glass Substrates by Pyrolysis of Camphor
Nam, Hyobin ; Lee, Woong ;
Korean Journal of Materials Research, volume 25, issue 7, 2015, Pages 341~346
DOI : 10.3740/MRSK.2015.25.7.341
The feasibility of obtaining graphitic carbon films on targeted substrates without a catalyst and transfer step was explored through the pyrolysis of the botanical derivative camphor. In a horizontal quartz tube, camphor was subjected to a sequential process of evaporation and thermal decomposition; then, the decomposed product was deposited on a glass substrate. Analysis of the Raman spectra suggest that the deposited film is related to unintentionally doped graphitic carbon containing some
linear carbon chains. The films were transparent in the visible range and electrically conductive, with a sheet resistance comparable to that of graphene. It was also demonstrated that graphitic films with similar properties can be reproduciblyobtained, while property control was readily achieved by varying the process temperature.
Analysis of Electrical Characteristics of Oxide Semiconductor of ZnO, SnO
Oh, Teresa ;
Korean Journal of Materials Research, volume 25, issue 7, 2015, Pages 347~351
DOI : 10.3740/MRSK.2015.25.7.347
To study the characteristics of ZTO, which is made using a target mixed
, the ZnO and
were analyzed using PL, XRD patterns, and electrical properties. Resulting characteristics were compared with the electrical characteristics of ZnO,
, and ZTO. The electrical characteristics of ZTO were found to improve with increasing of the annealing temperature due to the high degree of crystal structures at high temperature. The crystal structure of
was also found to increase with increasing temperatures. So, the structure of ZTO was found to be affected by the annealing temperature and the molecules of
; the optical property of ZTO was similar to that of ZnO. Among the ZTO films, ZTO annealed at the highest temperature showed the highest capacitance and Schottky contact.
Ohmic Contact Effect and Electrical Characteristics of ITO Thin Film Depending on SiOC Insulator
Oh, Teresa ;
Korean Journal of Materials Research, volume 25, issue 7, 2015, Pages 352~357
DOI : 10.3740/MRSK.2015.25.7.352
To research the characteristics of ITO film depending on a polarity of SiOC, specimens of ITO/SiOC/glass with metal-insulator-substrates (MIS) were prepared using a sputtering system. SiOC film with 17 sccm of oxygen flow rate became a non-polarity with low surface energy. The PL spectra of the ITO films deposited with various argon flow rates on SiOC film as non-polarity were found to lead to similar formations. However, the PL spectra of ITO deposited with various argon flow rates on SiOC with polarity were seen to have various features owing to the chemical reaction between ITO and the polar sites of SiOC. Most ITO/SiOC films non-linearly showed the Schottky contacts and current increased. But the ITO/SiOC film with a low current demonstrated an Ohmic contact.
Zinc Oxide Wire-Like Thin Films as Nitrogen Monoxide Gas Sensor
Hung, Nguyen Le ; Kim, Hyojin ; Kim, Dojin ;
Korean Journal of Materials Research, volume 25, issue 7, 2015, Pages 358~363
DOI : 10.3740/MRSK.2015.25.7.358
We present an excellent detection for nitrogen monoxide (NO) gas using polycrystalline ZnO wire-like films synthesized via a simple method combined with sputtering of Zn metallic films and subsequent thermal oxidation of the sputtered Zn nanowire films in dry air. Structural and morphological characterization revealed that it would be possible to synthesize polycrystalline hexagonal wurtzite ZnO films of a wire-like nanostructure with widths of 100-150 nm and lengths of several microns by controlling the sputtering conditions. It was found from the gas sensing measurements that the ZnO wire-like thin film gas sensor showed a significantly high response, with a maximum value of 29.2 for 2 ppm NO at
, as well as a reversible fast response to NO with a very low detection limit of 50 ppb. In addition, the ZnO wire-like thin film gas sensor also displayed an NO-selective sensing response for NO,
, and CO gases. Our results illustrate that polycrystalline ZnO wire-like thin films are potential sensing materials for the fabrication of NO-sensitive high-performance gas sensors.