• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.478-486
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• 1998

$CaTiO_3-x(La_{1/3}Nd_{1/3}TiO_3\;(0\le \textrm x\le0.8)$ system was prepared by reaction of $CaCO_3,\;LaO_3,\;Nd_2CO_3$ and ,TEX>$TiO_2$ mixture at 1673 K, which can be applied for microwave dielectric ceramic materials. The lattice parameters of(1-x))$CaTiO_3-x(La_{1/3}Nd_{1/3}TiO_3\;(0\le \textrm x\le0.8)$ system increased with the increase of x. Its structure was investigated by Rietveld profile-analysis of XRD in detail. Cations $ La^{3+}$ and Nd^{3+}$ were located at the $Ca^{2+}$ site in the range of $0\le \textrm x\le0.8$. crystal structure in $;(0\le \textrm x\le0.6)$ maintained space group Pnma with CaTiO_3 structure. The tiled and distorted $TiO_6$ was gradually released with the increase of x in $0\le \textrm x\le0.6$ .The structure was changed to a new space group of $Pmn2_1$ at the x value of 0.8. The relative dielectric constant $(\epsilon_r)$ of $(1-x)CaTiO_3-x(La_{1/3} Nd_{1/3})TiO_3$ ($(0\le \textrm x\le0.8)$) system was exponentially decreased by with the increased of x. The temperature coefficient of resonant frequency $(\tau_f)$ decreased with the increase of x in $0\le \textrm x\le0.6$ and then increased again at x=0.8 due to the change of crystal structure. The value of Q$\cdot f_o$ was 13800 (GHz) at x=0.2 and was very low under 2000 (GHz) in 0.4$\leq$x$\leq$0.8.

• Korean Journal of Materials Research
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• v.9 no.1
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• pp.3-7
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• 1999

The change of phosphorescent property with chemical modification and co-doping of Nd as an auxiliary activator in CaAl$_2$$O_4$: Eu\ulcorner, Nd\ulcorner phosphor, employing Nd\ulcornerion(0.6%) and an co-activator maintained its afterglow for 4.5 hours. And also the initial persistent brightness and phosphorescent property were further improved both by substituting Al by B atoms and incorporation of Nd\ulcorner ion. It was found that the persistent time was 30 hours for&Ca(Al_{0.97}\;B_{0.03}) $_2$$O_4$:EU\ulcorner(0.3%), Nd\ulcorner(0.6%) phosphor.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.1
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• pp.57-63
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• 2003

The effects of glass addition on the low-temperature sintering and microwave dielectric properties of $BaO-Nd_2O_3-TiO_2$ dielectric ceramics were studied. When 10∼13 wt% of lithium borosilicate glass was added, the sintering temperature decreased from 130$0^{\circ}C$to 850-$900^{\circ}C$relative density of more than 97% was obtained. When the sample was sintered at $850^{\circ}C$ with 10 wt% of glass, the dielectric properties of $\epsilon_r{\ge}54$, $Q{\times}f_0{\ge}2300$, and $\tau_f{\ge}+8ppm/^{\circ}C$ were obtained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.312-316
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• 1999

I-V characteristics of Praseodymium-based ZnO varistor doped with $Nd_2O_3$ in the range 0.0-2.0mol% sintered at 130$0^{\circ}C$ and 135$0^{\circ}C$ were investigated. In the all sides, ZnO varistors sintered at $1300^{\circ}C$ exhibited much better varistor characteristics than that at 135$0^{\circ}C$. All ZnO varistors doped with $Nd_2O_3$ sintered at $1300^{\circ}C$ exhibited good varistor characteristics but particularly ZnO varistor doped with l.Omol% $Nd_2O_3$ exhibited the best characteristics, which the nonlinear is 65.2 and the leakage current is 4.5pA. It is estimated that ZnO varistor doped with l.Omol% $Nd_2O_3$ will begin to be sufficiently used as basic composition to fabricate a good varistor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.243-243
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• 2007

We have studied the electrical properties and microstructure of $(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_2Cu_3O_y[(YNS)-123]$ Oxides by rod-type seeded melt growth process(RSMG) in air atmosphere. Rod-type $NdBa_2Cu_3O_y${Nd-123) seed crystals made a extrusion process method, were used for achieving the ab-plane alignment having large grains perpendicular to the center of (YNS)-123 samples. The observations using SEM and TEM micrographs of the melt-textured (YNS)-123 samples revealed that the nonsuperconducting $(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_2Cu_3O_y[(YNS)-211]$ inclusions are uniformly distributed in the superconducting matrix. The microstructure and electrical properties were investigated by XRD, SEM, TEM and DC SQUID magnetometer. The sample showed a sharp superconducting transition at 90 K. The magnetization values of the (YNS)-123 sample exhibited the enhanced electrical properties, compared with $YBa_2Cu_3O_y$(Y-123) sample.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.11
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• pp.947-953
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• 1998

The microwave dielectric properties of X BaO-0.15($Nd_{0.87}Bi_{0.13})_2O_3-(0.85-X)TiO_2 (X=0.14~0.17) and 0.16BaO-0.15(Bi_xNd_{1-x})_2O_3-0.69TiO_2$ (X=0.12~0.15) ceramics sintered at 1320~$1380^{\circ}C$ were investigated. The microwave dielectric properties of X BaO-0.15(Nd_{0.87}Bi_{0.13})_2O_3-(0.85-X)TiO_2$ (X=0.14~0.17) can be controlled effectively by adjusting X content : with increasing X from 0.14 to 0.17 both dielectric constant and temperature coefficient of resonant frequency decreased from 94.6 to 86 and from 22 ppm/^${\circ}C to -7 ppm/^{\circ}C$, respectively, while quality factor increased from 1300 to 1920 (at 4GHz). The microwave dielectric properties of 0.16BaO-0.15(Bi_x/Nd_{1-x2}O_3 -0.69TiO_2$ (X=0.12~0.15) can be controlled effectively by adjusting X content : with increasing X from 0.12 to 0.15 both quality factor and temperature coefficient of resonant frequency decreased from 1920 to 1430 and from 9 ppm/^${\circ}C to -10 ppm/^{\circ}C$, respectively, while dielectric constant increased from 87.5 to 92.6.

• Progress in Superconductivity and Cryogenics
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• v.11 no.2
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• pp.1-6
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• 2009

We report a successful fabrication of $high-J_c\;NdBa_2Cu_3O_{7-{\delta}}$ (NdBCO) films on $SrTiO_3$(STO) (100) substrates by pulsed laser deposition (PLD) in a relatively wide processing window. Under various oxygen pressures controlled by either 1%$O_2$/Ar mixture gas or pure $O_2$ gas, strongly c-axis oriented NdBCO films were grown at the substrate temperature $(T_s)\;of\;800^{\circ}C$ in 800 mTorr with 1%$O_2$/Ar gas and also in 400 and 800 mTorr with pure $O_2$ gas. These samples exhibited $T_c$ values over 90K and $J_c$ values of $2.8-3.5MA/cm^2$ at 77K in self-field (77K, sf). On the other hand, $J_c$ values over $1A/cm^2$ were obtained at the temperature regions of $700-830^{\circ}C$ in 800 mTorr with 1%$O_2$/Ar gas at those of $750-830^{\circ}C$ in 800 mTorr with pure $O_2$ gas. Unlike previous reports, resent results support that the PLD processing window for high-Jc NdBCO films is not narrow.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.30.2-30
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• 2002

• Journal of the Korean Ceramic Society
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• v.36 no.2
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• pp.210-219
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• 1999

The fundamental dispersion property of Si2N4 and a combination of AlN and Nd2O3 as sintering additives in a variety of organic solvents such as alcohols, hydrocarbons, ketones, and ethers was investigated. The stabilization mechanism and interaction between organic functional groups of the various organic additives were studied to clarify the dispersibility of the ceramic particles in the nonaqueous suspending medium. characterization of the suspensions was based mainly on electrokinetic sonic amplitude(ESA) measurements and the flow curves obtained from the rheological studies as well as estimated Hamaker constants. It was found that the contribution of electrostatic repulsive forces to the Si3N4, AlN and Nd2O3 stabilization in organic media is appreciably greater than anticipated and is dependent on the physicochemical properties of organic solvents.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1171-1172
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• 2006

Addition of 2.0wt%$Dy_2O_3$ or 0.3wt%Sn proved to be very effective in improving the permanent magnetic properties of NdFeNbB magnets. $Dy_2O_3$ additions result in the increase in the Hci and temperature dependence due to formation of (NdDy)-rich phase and grain refinement of $\Phi$ phase. This improvement of the coercivity stability of the magnets from the addition of Sn is attributed to the smoothing effect of the Sn addition at the grain boundaries. The magnetic properties, the temperature dependence and Curie temperature of NdFeNbB with $Dy_2O_3$ and Sn combined addition were found to be considerably improved.