Browsing by Author "CHIOU, BS"

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A SALT SPRAY TEST ON INTERLAYER-MODIFIED TIN COATING
(1992-06-15)
CHEN, YI
;
DUH, JG
;
CHIOU, BS
;
YANG, TJ
;
電控工程研究所
A ZNO VARISTOR DERIVED FROM METAL-OXIDE DIFFUSION
(1989-06-14)
CHIOU, BS
;
CHEN, TC
;
DUH, JG
;
電控工程研究所
;
Institute of Electrical and Control Engineering
ADMITTANCE SPECTROSCOPY AND TRAPPING PHENOMENA OF ZNO BASED VARISTORS
(1991-10-01)
CHIOU, BS
;
CHUNG, MC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Electrical properties of ZnO varistors are investigated through admittance spectroscopy. The observed ac admittance dispersion is caused by the existence of two deep bulk trap levels, which are 0.31 eV and 0.245 eV, respectively, below the conduction band. The 0.31 eV level is associated with the oxygen vacancy while the origin of the 0.245 eV level is not yet clear. An equivalent circuit model for ZnO varistors is proposed that is based on the existence of deep bulk traps.
ANALYSIS OF TRANSPORT CRITICAL-CURRENT DENSITY IN A BENT BI-PB-SR-CA-CU-O SILVER-SHEATHED TAPE
(1995-06-01)
LEE, WD
;
HORNG, L
;
YANG, TJ
;
CHIOU, BS
;
電子物理學系
The experimental results on the magnetic behavior of the transport critical current density in a bent Bi based superconducting tape have shown that the irreversible strain limit epsilon(irrev) for the onset of permanent strain damage to Ag sheathed superconductors is not dependent on the magnetic field, nor does the normalized I-c(H, epsilon)/I-c(0, epsilon) current depend on the strain at least up to 0.5 T at 77 K. Such a behavior has been attributed to two reasons: (1) The intrinsic pinning properties are unchanged in a bent tape; (2) The strain effect is extrinsic and arises from superconductor cracks. Thus, based on these arguments a Josephson junction tunneling model with cracks in between the grain boundaries is proposed to explain the J(c) behavior quite well for a bent granular high-T-c superconducting tape. Our model calculation shows that the critical current density of high-T-c superconductor may be enhanced by increasing the strain tolerance epsilon(irrev) and the epsilon(irrev) is determined by the properties of Ag sheathed tape and its related material parameters, which are dependent on the connectivity of the grain boundaries.
ANISOTROPIC IRREVERSIBILITY LINES FOR C-AXIS ALIGNED (BI, PB)2CA2SR2CU3O10+DELTA POWDERS
(1992-04-15)
SHI, JB
;
CHIOU, BS
;
KUO, PL
;
KU, HC
;
電控工程研究所
Anisotropic irreversibility lines due to thermal fluctuation for quasi-two-dimensional high-T(c) superconductors were observed in c-axis-aligned powders of the (Bi, Pb)2Ca2Sr2Cu3O10+deltaBi(2223) compound with T(c) = 108 K. The anisotropic ratio H(r)(perpendicular-to c)/H(r)(parallel-to c) decreases sharply from 13.6 at 100 K to low values of 3.2 at 80 K and 3.1 at 70 K. The simple 3D-like power law H(r)=a.(1 - T/T(c))n was observed only in the low field region (less-than-or-equal-to 200 G) with n=2.19 for H perpendicular-to c and 2.99 for H parallel-to c. In the higher field region up to 4 kG, the temperature dependence of H(r)(T) lines changes into a 2D-like exponential function H(r) = b.exp (-T/T0) due to the breakdown of the interlayer and/or intralayer coupling of the conduction channel which consists of three Cu-0 planes, with T0 = 14.2 K for H perpendicular-to c and 13.7 K for H parallel-to c. The magnetic susceptibility ratio chi(c)/chi(ab) for this highly anisotropic superconductor in a low applied field of 8 G increases sharply from 9.8 at 5 K to 17.9 near T(c).
ANISOTROPIC IRREVERSIBILITY LINES FOR C-AXIS ALIGNED POWDERS OF THE BI(2223) COMPOUND (BI,PB)2CA2SR2CU3O10+DELTA
(1991-12-01)
SHI, JB
;
KUO, PL
;
CHIOU, BS
;
KU, HC
;
電控工程研究所
Anisotropic irreversibility lines were observed for c-axis aligned powders of the Bi(2223) compound (Bi,Pb)2Ca2Sr2Cu3O10+delta (T(c) = 108 K). The aligned sample was prepared using powders embedded in epoxy and aligned in a 9.4 T applied magnetic field at room temperature. The anisotropic irreversibility lines H(r)(T) were measured with applied field H parallel and perpendicular to the c-axis. The simple power law H(r) = a.(1 - T/T(c))n with n = 2.19 (H perpendicular-to c) and n = 2.99 (H parallel-to c) were observed only in low applied field H less-than-or-equal-to 250 G. For applied field up to 4 kG, H(r)(T) lines were better fitted with the exponential law H(r) = b.exp(-T/t).
ANISOTROPIC MAGNETIC-PROPERTIES OF BI2SR2CUO6+DELTA SINGLE-CRYSTAL
(1992-07-01)
SHI, JB
;
CHIOU, BS
;
HO, JC
;
KU, HC
;
電控工程研究所
Single crystals of Bi2Sr2CuO6+delta were synthesized and characterized by X-ray diffraction. The Bi(2201) sample remains not superconducting or magnetically ordered down to 5 K. With an applied magnetic field perpendicular or parallel to the c-axis, magnetic measurements yielded anisotropic magnetic susceptibilities chi(c)(H perpendicular-to c) and chi(ab)(H parallel-to c). Both can be fitted to the sum of a temperature-independent chi(0) and a Curie-Weiss term C/(T + theta(p)) in the temperature range between 5 and 300 K, with a common Curie constant C = 1.0 x 10(-2) cm3 K/mol and Curie-Weiss paramagnetic intercept theta(p) = + 1.1 K. Since the resulting Curie-Weiss term is the same for both directions, the overall anisotropy DELTA(chi) = chi(c) - chi(ab) = DELTA(chi-0) is also temperature independent. Its magnitude, 3.3 x 10(-5) cm3/mol, however, is lower than the corresponding values for Bi(2212) (2.3 x 10(-4) cm3/mol) and Bi(2223) (5.8 x 10(-4) cm3/mol).
ANISOTROPIC SUPERCONDUCTING PROPERTIES OF ALIGNED (BI,PB)2CAN-1SR2CUNO2N+4+DELTA POWDERS (N = 1, 2, 3) WITH TC = 32, 94, AND 110 K
(1991-06-01)
SHI, JB
;
CHIOU, BS
;
KU, HC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The anisotropic superconducting properties of aligned powders embedded in epoxy for bismuth copper oxides with the compositions (Bi1.6Pb0.4)(Sr1.5La0.5)CuO6+delta (n = 1, T(c) = 32 K), Bi2Ca1.2Sr1.8Cu2O8+delta (n = 2, T(c) = 94 K), and (Bi1.85Pb0.15)Ca2.2Sr1.8Cu3O10+delta (n = 3, T(c) = 110 K) are reported. These c-axis-aligned samples were prepared in a 9.4-T applied magnetic field at room temperature The temperature dependence of the anisotropy ratio chi-c(T)/chi-ab(T) in the superconducting state is derived from both zero-field-cooled and field-cooled data using a small applied field H (less than or equal to the lower critical field H(c1)) parallel and perpendicular to the orthorhombic c axis. A highly anisotropic chi-c/chi-ab ratio was observed for all three systems, the maximum value of chi-c/chi-ab = 9.8 at 5 K and 10.8 at 85 K for the 2:2:2:3 compound (Bi1.85Pb0.15)Ca2.2Sr1.8Cu3O10+delta was observed. The field dependence of the anisotropy ratio chi-c(H)/chi-ab(H) for the 2:1:2:2 compound Bi2Ca1.2Sr1.8Cu2O8+delta up to 5 kG is discussed.
ANOMALOUS PR ORDERING IN THE NEW TLBA2PRCU2O7-DELTA COMPOUND
(1992-11-01)
LAI, CC
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CHIOU, BS
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CHEN, YY
;
HO, JC
;
KU, HC
Magnetic measurements on the new tetragonal Tl(1212) compound TlBa2PrCu2O7-delta (a = 3.910 angstrom and c = 12.53 angstrom) reveal an anomalously high antiferromagnetic Neel temperature T(N) congruent-to 8 K. This transition temperature is higher than T(N) = 2.2 K for isostructural TlBa2GdCu2O7-delta. Corroborative evidence comes from calorimetric studies, in which a magnetic entropy was obtained DELTAS congruent-to 0.5 Rln 2 between 2 and 10 K, as well as a sizeable linear term in specific heat comparable to those found in heavy-fermion systems. Through structural consideration, these observations can not only be correlated to the almost identical but still puzzling features of PrBa2Cu3O7-y, but also remove some ambiguity in the interpretation of earlier results.
BARRIER EFFECT OF E-BEAM EVAPORATED TUNGSTEN INTERLAYER IN AL/W/PTSI METALLIZATION LAYER
(1988-09-01)
CHIOU, BS
;
LO, HS
;
CHANG, PH
;
電控工程研究所
;
Institute of Electrical and Control Engineering
CATALYTIC AND GAS SENSING CHARACTERISTICS IN PD-DOPED SNO2
(1989-09-01)
DUH, JG
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JOU, JW
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CHIOU, BS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
CHARACTERISTICS OF PD-DOPED TIN OXIDE CERAMICS IN RESPONSE TO CO GAS
(1988-11-01)
CHIOU, BS
;
LI, JJ
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DUH, JG
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電控工程研究所
;
Institute of Electrical and Control Engineering
CHARACTERISTICS OF TITANIUM SILICIDE FORMED BY SI/MO/TI TRILAYER METALLIZATION
(1989-03-01)
CHIOU, BS
;
YANG, BJ
;
CHANG, PH
;
交大名義發表
;
電子物理學系
COBALT ORDERING IN LAYERED BI2SR2COO6+DELTA-SINGLE CRYSTAL
(1993-01-15)
SHI, JB
;
HO, JC
;
LEE, TJ
;
CHIOU, BS
;
KU, HC
Insulating Bi2Sr2CoO6+delta is nearly isomorphic with the Bi(2201)-type high-T(c) superconductors. Magnetic and calorimetric studies were carried out on single crystal samples of this layered compound. Based on magnetic measurements, the cobalt ions undergo a canted antiferromapetic ordering at T(N) = 159 K. A low-temperature neutron diffraction study of the magnetic structure is in progress. The molar magnetic susceptibility chi(ab)(H perpendicular-to c) above 200 K can be well fitted by the Curie-Weiss form chi(ab)(T) = chi0+C/(T-theta(p)), with chi0 = 0.56 cm3K/mol, Curie constant C = 3.2 x 10(-2) cm3K/mol and Curie-Weiss intercept theta(p) = 159 K. There is no magnetic specific heat peak, however, prevailing around T(N). This anomalous calorimetric behavior is attributed to the two-dimensional quantum spin fluctuation of Co spins above T(N) in the layered compound as previously observed for Cu spins in (Gd1.85Ce0.15)CuO4-delta and La2CuO4-delta.
CORROSION BEHAVIOR OF ELECTROLESS NICKEL-PLATING MODIFIED TIN COATING
(1993-09-01)
DOONG, JC
;
DUH, JG
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TSAI, SY
;
WANG, JH
;
CHIOU, BS
TiN films were prepared by reactive r.f. magnetron sputtering on low carbon steel substrates. An electroless Ni-P plating was introduced as the interlayer in the modification of the TiN coating. The corrosion behaviour of the TiN coating assembly was evaluated using the salt spray test and the polarization technique. For a thicker Ni-P interlayer (greater than 5 mum), no appreciable corrosion was observed up to hundreds of hours after salt spray testing. The polarization curve indicates a barrier-type passive film in the TiN/Ni3P/Fe coating assembly. The corrosion currents for TiN/Fe, Ni3P/Fe and TiN/Ni3P/Fe are 200, 40-70 and 6-7 muA cm-2 respectively. It appears that the electroless Ni-P interlayer modified TiN coating has better anticorrosion resistance than pure TiN coating on low carbon steel.
DEHYDRATION OF SYNTHESIZED CALCIA-STABILIZED ZIRCONIA FROM A COPRECIPITATION PROCESS
(1986-09-01)
CHIOU, BS
;
HSU, WY
;
DUH, JG
;
電控工程研究所
;
Institute of Electrical and Control Engineering
DEHYDRATION OF SYNTHESIZED COPRECIPITATED TITANIA POWDERS
(1989-04-01)
CHIOU, BS
;
TSAI, YJ
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交大名義發表
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電控工程研究所
;
National Chiao Tung University
DEPOSITION OF INDIUM TIN OXIDE-FILMS ON ACRYLIC SUBSTRATES BY RADIOFREQUENCY MAGNETRON SPUTTERING
(1994-07-01)
CHIOU, BS
;
HSIEH, ST
;
WU, WF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Indium tin oxide (ITO) films were deposited onto acrylic substrates by rf magnetron sputtering. Low substrate temperature (<80-degrees-C) and low rf power (<28 W) were maintained during sputtering to prevent acrylic substrate deformation. The influence of sputtering parameters, such as rf power, target-to-substrate distance, and chamber pressure, on the film deposition rate, the electrical properties, as well as the optical properties of the deposited films was investigated. Both the refractive index and the extinction coefficient were derived. The high reflection at wavelengths greater than 3 mum made these sputtered ITO films applicable to infrared mirrors.
DEVELOPMENT OF TEMPERATURE-STABLE THICK-FILM DIELECTRICS .1. LOW-K DIELECTRIC
(1989-12-01)
CHIOU, BS
;
交大名義發表
;
電控工程研究所
;
National Chiao Tung University
;
Institute of Electrical and Control Engineering
DEVELOPMENT OF TEMPERATURE-STABLE THICK-FILM DIELECTRICS .2. MEDIUM-K DIELECTRIC
(1989-12-01)
CHIOU, BS
;
交大名義發表
;
電控工程研究所
;
National Chiao Tung University
;
Institute of Electrical and Control Engineering