• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.843-846
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• 2000

The (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.02∼0.08) ceramics were fabricated by conventional mixed oxide method. The sintering temperature and time were 1250$^{\circ}C$∼1400$^{\circ}C$, 2hr., respectively. The structural and microwave dielectric properties were investigated by varying sintering temperature and composition ratio. In the (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.02) ceramics, the cubic SrTiO$_3$and hexagonal MgTiO$_3$phases were coexisted. The dielectric constant was increased and the temperature coefficient of resonant frequency( $\tau_f$) was decreased with addition of SrTiO$_3$. The temperature coefficient of resonant frequency($\tau_f$) was gradually varied from negative value to positive value with increasing the SrTiO$_3$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.547-550
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• 2000

The (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.03~0.04) ceramics were fabricated by the conventional mixed oxide method. The sintering temperature and time were 125$0^{\circ}C$~135$0^{\circ}C$, 2hr., respectively. From the X-ray diffraction patterns, it was found that the perovskite SrTiO$_3$ and ilmenite MgTiO$_3$ structures coexisted in the (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.03~0.04) ceramics. The dielectric constant($\varepsilon$$_{r}$) was increased with addition of SrTiO$_3$. The temperature coefficient of resonant frequency($\tau$$_{f}$) was gradually varied from negative value to the positive value with increasing the SrTiO$_3$. The negative temperature coefficient of resonant frequency of the magnesium titanate was adjusted to near zero at x=0.036, where the dielectric constant, quality factor, and $\tau$$_{f}$ were 20.65, 95120, and +1.3ppm/$^{\circ}C$, respectively. The temperature stability of qualify factor in (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.03~0.04) ceramics increased as the amount of MgTiO$_3$./TEX>.

• 한국전기전자재료학회논문지
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• 제18권6호
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• pp.538-542
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• 2005

The structural and microwave dielectric properties of $0.7Mg_4Ta_2O_9-0.3SrTiO_3$ ceramics with sintering temperature were investigated. All the sample of the $0.7Mg_4Ta_2O_9-0.3SrTiO_3$ ceramics were prepared by conventional miked oxide method and the sintering temperature was $1425\~1500^{\circ}C$. The hexagonal phase of $Mg_4Ta_2O_9$ and the cubic phase of $SrTiO_3$ were coexisted. The porosity of $0.7Mg_4Ta_2O_9-0.3SrTiO_3$ ceramics were reduced with increasing sintering temperature. In the case of $0.7Mg_4Ta_2O_9-0.3SrTiO_3$ ceramics sintered at $1475^{\circ}C$, dielectric constant, quality factor and temperature coefficient of resonant frequency were 14.51, 82,596 GHz and $-3.14\;ppm/^{\circ}C$, respectively.

• 한국전기전자재료학회논문지
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• 제13권12호
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• pp.1011-1016
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• 2000

The (1-x)MgTi $O_3$-xSrTi $O_3$(x=0.02~0.08) ceramics were fabricated by the conventional mixed oxide method. The sintering temperature and time were 125$0^{\circ}C$~1375$^{\circ}C$ and 2hours. The structure and microwave dielectric properties were investigated with sintering temperature and composition ratio. From the X-ray diffraction patterns, the cubic SrTi $O_3$and hexagonal MgTi $O_3$structures were coexisted in the (1-x)MgTi $O_3$-xSrTi $O_3$(x=0.02~0.08) ceramics. The dielectric constant($\varepsilon$$_{r}$) was increased and the temperature coefficient of resonant frequency($\tau$$_{f}$)was decreased with addition of SrTi $O_3$. The temperature coefficient of resonant frequency($\tau$$_{f}$) was gradually varied from negative value to positive value with increasing SrTi $O_3$. In the case of 0.96MgTi $O_3$-0.04SrTi $O_3$ceramics sintered at 130$0^{\circ}C$, the dielectric constant, quality factor and temperature coefficient of resonant frequency were 20.5, 5918(at 7.33GHz) and +10ppm/$^{\circ}C$, respectively.y.y.y.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1485-1487
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• 2002

The 0.96Mg$TiO_3$-0.04Sr$TiO_3$ ceramics with $V_2O_5$(5wt%) were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature by XRD and SEM. According to the X-ray diffraction patterns of the 0.96Mg$TiO_3$-0.04Sr$TiO_3$ceramics with $V_2O_5$(5wt%), the ilmenite $MgTiO_3$ and perovskite $SrTiO_3$ structures were coexisted and secondary phase $MgTi_2O_5$ were appeared. Increasing the sintering temperature, the grain size was increased and three types of grains were exhibited: larger circular grain, small square grain and lapth-shaped grain. In the case of 0.96Mg$TiO_3$-0.04Sr$TiO_3$ ceramics with $V_2O_5$(10wt%), dielectric constant, quality factor and temperature coefficient of resonant frequency were $15.24{\sim}18.55$, $22,890{\sim}42,100$GHz, -24.5${\sim}$+2.414ppm/$^{\circ}C$, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.430-433
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• 2001

The $0.96MgTiO_{3}-0.04SrTiO_{3}+xCe(x=0{\sim}1.6wt%)$ ceramics were fabricated by the conventional mixed oxide method. The sintering temperature and time were $1300^{\circ}C$, 2hr., respectively. From the X-ray diffraction patterns, it was found that the perovskite $SrTiO_{3}$ and ilmenite $MgTiO_{3}$ structures were coexisted in the $0.96MgTiO_{3}-0.04SrTiO_{3}+xCe(x=0{\sim}1.6wt%)$ ceramics. The dielectric constant$(\varepsilon_{r})$ was increased with addition of Ce. The temperature coefficient of resonant frequency$(\Gamma_{f})$ was gradually varied from positive value to the negative value with increasing the Ce. The temperature coefficient of resonant frequency of the $0.96MgTiO_{3}-0.04SrTiO_{3}+0.2Ce$ ceramics was near zero, where the dielectric constant, quality factor, and $\Gamma_{f}$ were 20.68, 50,272 and ${-0.5ppm/^{\circ}C}$, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.430-433
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• 2001

The 0.96MgTiO$_3$-0.04SrTiO$_3$+xCe(x=0∼1.6 wt%) ceramics were fabricated by the conventional mixed oxide method. The sintering temperature and time were 1300$^{\circ}C$, 2hr., respectively. From the X-ray diffraction patterns, it was found that the perovskite SrTiO$_3$ and ilmenite MgTiO$_3$ structures were coexisted in the 0.96MgTiO$_3$-0.04SrTiO$_3$+xCe(x=0∼1.6 wt%) ceramics. The dielectric constant($\varepsilon$$\sub$r/) was increased with addition of Ce. The temperature coefficient of resonant frequency($\tau$$\sub$f/) was gradually varied from positive value to the negative value with increasing the Ce. The temperature coefficient of resonant frequency of the 0.96MgTiO$_3$-0.04SrTiO$_3$+0.2Ce ceramics was near zero, where the dielectric constant, quality factor, and $\tau$$\sub$f/ were 20.68, 50, 272 and -0.5pm/$^{\circ}C$, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.282-285
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• 1999

The (1-x)MgTiO$_3$-xSrTiO$_3$(x=0,0.1) ceramics were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature and composition ratio by XRD, SEM and DT-TGA. Increasing the sintering temperature from 130$0^{\circ}C$ to 1$600^{\circ}C$, second phase was decreased and grain size was increased. In the case of 0.9 MgTiO$_3$-0.1SrTiO$_3$ ceramics sintered at 130$0^{\circ}C$, dielectric constant, quality factor and temperature coefficient of resonant frequency were 22.61, 10,928(at 1GHz), +50.26ppm/$^{\circ}C$ , respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1774-1776
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• 1999

The (1-x)$MgTiO_3-SrTiO_3$ (x=0,0.1,0.2,0.3) ceramics were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature and composition ratio by XRD, SEM and DT-TGA. Increasing the sintering temperature from $1300^{\circ}C$ to $1600^{\circ}C$, second phase was decreased and grain size was increased. The average grain size of the $0.8MgTiO_3-0.2SrTiO_3$ ceramics sintered at $1600^{\circ}C$ were $3.61{\mu}m$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.953-955
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• 1999

The (1-x)$MgTiO_3-SrTiO_3$ (x=0. 0.1, 0.2, 0.3) ceramics were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature and composition ratio by XRD, SEM and BT-TGA. Increasing the sintering temperature from $1300^{\circ}C$ to $1600^{\circ}C$, second phase was decreased and grain size was increased. The average gram size of the 0.8$MgTiO_3-SrTiO_3$ ceramics sintered at $1600^{\circ}C$ were $3.61{\mu}m$.