• Journal of the Korean Ceramic Society
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• v.37 no.6
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• pp.552-558
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• 2000

LiMn2O4 thin fiolm cathodes for Li-ion secondary battery were fabricated by r.f. magnetron sputtering technique. As-deposited films were amorphous. A spinel structure could not be obtained LiMn2O4 films by in-situ thermal annealing. After post thermal annealing over $700^{\circ}C$ in oxygen atmosphere, LiMn2O4 films prepared above 100 W r.f. power could be crystallized into a spinel structure. The electrochemical property of the LiMn2O4 film cathodes was tested in a Li/1 M LiClO4 in PC/LiMn2O4 cell. From cyclic voltammetry at scan rate of 2mV/sec of 2.5~4.5V, LiMn2O4 electrode prepared by post annealing at 75$0^{\circ}C$ showed good initial capacity. LiMn2O4 electrode prepared by post annealing at 80$0^{\circ}C$ showed the best crycling performance.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.191.1-191
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• 2000

• Korean Journal of Materials Research
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• v.14 no.11
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• pp.821-827
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• 2004

Titanium oxide thin films were prepared on Si(100) substrates by R.F. magnetron reactive sputtering at $30\sim200watt$ R.F power range, and annealed at $600^{\circ}C\sim800^{\circ}C$ for 1 hour. The properties of $TiO_2$ thin films were analyzed using x-ray, ${\alpha}-step$, ellipsometer, scanning electron microscopy, and FT-IR spectrometer. Upon in-situ depositions, the initial phase of $TiO_2$ thin film showed non-crystalline phase at R.F. power $30\sim100$ watt. The crosssection of $TiO_2$ thin films were sbserved to be the columnar structure. With the increasing R.F power and annealing temperature, the grain size, crystallinity, refractive index, and void size of titanium oxides showed a tended to increase. The FT-IR transmittance spectra of titanium oxide thin films have the obsorption band of Ti-O bond, Si-O bond, Si-O-Ti bond and O-H bond. With the increase of R.F. power and annealing temperature, these films have the stronger bond structures. It is considered that such a phenomena is due to phase transition and good crystallinity

• Proceedings of the Korean Ceranic Society Conference
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• 2004.04b
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• pp.41.1-41.1
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• 2004

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.219.1-219
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• 2003

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.11a
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• pp.55-55
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• 1996

• Journal of Sensor Science and Technology
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• v.14 no.2
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• pp.63-68
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• 2005

The nano-grained Pd or Pt-doped $SnO_{2}$ thin films were deposited on the alumina substrate at ambient temperature or $300^{\circ}C$ by using an R.F. magnetron sputtering system and then annealed at $650^{\cir}C$ for 1 hour or 4 hours in air. The crystallinity and microstructure of the annealed films were analyzed. A grain size of the thin films was 30 nm to 50 nm. As a result of gas sensitivity measurements to an alcohol vapor of $36^{\circ}C$, the 2 wt.% Pt-doped $SnO_{2}$ thin-film sensor deposited at $300^{\circ}C$ and annealed at $650^{\circ}C$ for 4 hours showed the highest sensitivity.

• Journal of the Korean Ceramic Society
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• v.39 no.4
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• pp.394-400
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• 2002

Tin oxide thin films doped with silicon as anodes for lithium secondary battery were fabricated by R. F. magnetron sputtering technique. The electrochemical results for lithium secondary battery anodes showed that addition of silicon decreases the oxidic state of tin, and, hence, reduced the irreversible capacity during the first discharge/charge cycle. The (110),(101),(211) planes were grown with increasing substrate temperatures. The reversible capacity of thin films fabricated in conditions of $300^{\circ}C$ substrate temperature and 7:3 $Ar:O_2$ ratio was 700 mAh/g.

• Journal of the Korean Ceramic Society
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• v.39 no.9
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• pp.840-845
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• 2002

As an ozone gas sensor, the semiconductor gas sensor which is cheap, portable and simple in use and has a high sensitivity and an excellent selectivity, has been known as an alternative. In the present study, ITO ($In_2O_3 95%,\;SnO_2$ 5%) thin films were deposited on the alumina substrate by using R.F. magnetron sputtering method. The substrate temperature was 300$^{\circ}C$ and 500$^{\circ}C$, respectively and then some specimens were annealed at 500$^{\circ}C$ for 4h in air. ITO gas-sensing films formed crystallines before and after annealing. As results of gas sensitivity measurements to an ozone gas, the sensor deposited at 300$^{\circ}C$ and then annealed has the highest sensitivity (sensible below 1 ppm). As the operating temperature increased gradually, the sensitivity decreased but the response time and stability improved.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.05a
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• pp.115-115
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• 1998