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1.
Films of (1−x)Pb(Zn1/3Nb2/3)O3-xPb(Zr0.4Ti0.6) O3 (x = 0.6, 40PZN-60PZT) were deposited on Pt/TiO2/ SiO2/Si substrate through spin coating. Using a combination of homogeneous precursor solution preparation and two-step pyrolysis
process, we were able to obtain the 40PZN-60PZT thin films of perovskite phase virtually without pyrochlore phase precipitation
after annealing above 650∘C. But since annealing done at the high temperatures for extended time can cause diffusion of Pt, TiO2 and Si, and precipitation of nonstoichiometric PbO, we adopted 2-step annealing method to circumvent these problems. The
2-step annealed films show dense microstructure than the 1-step films annealed at higher temperature. Furthermore, the root-mean-square
surface roughness of 220 nm thick films which are annealed at 720∘C for 1 min and then annealed at 650∘C for 5 min was found to be 3.9 nm by atomic force microscopy as compared to the 12 nm surface roughness of the film annealed
only at 720∘C for 5 min. The electrical properties of 2-step annealed films are virtually same and those of the 1-step annealed films
annealed at high temperature. The film 2-step annealed at 720∘C for brief 1 min and with subsequent annealing at 650∘C for 5 min showed a saturated hysteresis loop at an applied voltage of 5 V with remanent polarization (P
r) and coercive voltage (V
c) of 25.3 μC/cm2 and 0.66 V respectively. The leakage current density was lower than 10−5A/cm2 at an applied voltage of 5 V. 相似文献
2.
Ferroelectric Ba0.5Sr0.5TiO3 (BST) films were prepared on Pt/Ti/SiO2/Si substrates by the sol-gel process. The films were spin-coated at 2000 rpm for 30 secs and then pyrolysed for 5 mins at
the temperature of 350∘C. This coating procedure was repeated for 3, 4, 5 and 6 times to obtain BST films with different thicknesses. After coating
the films with the desired repetition times, the films were finally annealed in a conventional furnace at temperatures ranging
from 600∘C to 800∘C with a 50∘C interval in between. The films obtained with an annealing procedure of 750∘C were polycrystalline with the presence of an impurity BaCO3 phase. The capacitance and leakage current were measured and used to extract information on the metal-BST interface. With
the series capacitance model and modified Schottky emission equation, the thickness of the dead layers for Au/BST and Pt/BST
interfaces were calculated to be less than 6 nm and 5 nm, respectively. 相似文献
3.
The amorphous films were annealed in a wide temperature range (250–1000∘C) and film properties of TiO2 thin films were studied. Nano-sized anatase polycrystallites had been induced by thermal annealing for the films annealed
at and above 300∘C as confirmed by X-ray diffraction. Strong LO-phonon Raman modes, especially B1g
(395 cm−1) and E
g
(636 cm−1) in Raman spectra and the absorption peak at 436 cm−1 in absorbance spectra by Fourier transform infrared spectroscopy also indicated the existence of anatase phase in crystalline
thin films. In addition, with the increase of the annealing temperature, the wettability of the film surface was enhanced
as shown by the decrease of water contact angle from over 90∘ to less than 40∘. Moreover, upon UV laser irradiation on film surface, the water contact angle saturated at 10∘ indicative of a highly hydrophilic surface for all the films, which arose from the dissociative adsorption of water molecules
on the defect sits of the surface generated by the photocatalysis reactions of TiO2. This behavior makes the film a good potential candidate for self-clean coatings. 相似文献
4.
High-performance pyroelectric infrared detectors have been fabricated using Lithium tantalite (LiTaO3) thin films deposited on Pt(111)/Ti/SiO2/Si(100) substrates by diol-based sol-gel method and rapid thermal annealing (RTA) technique. The dielectric and pyroelectric
properties of IR detectors of LiTaO3 thin films crystallized by conventional and RTA processes are investigated. Experimental results reveal that the heating
rate will influence strongly on dielectricity and pyroelectricity of LiTaO3 thin films. The voltage responsivities (Rv) measured at 80 Hz increase from 5496 to 8455 V/W and the specific detecivities
(D∗) measured at 300 Hz increase from 1.94 × 108 to 2.38 × 108 cmHz1/2/W with an increase of heating rate from 600 to 1800∘C/min. However, the voltage responsivity and the specific detecivity decrease with heating rate in excess of 1800∘C/min. The results show that the LiTaO3 thin film detector with a heating rate of 1800∘C/min exists both the maximums of voltage responsivity and specific detecivity. 相似文献
5.
G. X. Liu F. K. Shan J. J. Park W. J. Lee G. H. Lee I. S. Kim B. C. Shin S. G. Yoon 《Journal of Electroceramics》2006,17(2-4):145-149
Ga2O3 and Ga2O3-TiO2 (GTO) nano-mixed thin films were prepared by plasma enhanced atomic layer deposition with an alternating supply of reactant
sources, [(CH3)2GaNH2]3, Ti(N(CH3)2)4 and oxygen plasma. The uniform and smooth Ga2O3 and GTO thin films were successfully deposited. Excellent step coverage of these films was obtained by chemisorbed chemical
reactions with oxygen plasma on the surface. The dielectric constant of GTO thin film definitely increased compared to Ga2O3 film, and the leakage currents of GTO films were comparable to Ga2O3 films. The leakage current density of a 40-nm-GTO film annealed at 600∘C was approximately 1×10−7 A/cm2 up to about 600 kV/cm. 相似文献
6.
Bo-Yun Jang Beom-Jong Kim Young-Hun Jeong Sahn Nahm Ho-Jung Sun Hwack-Ju Lee 《Journal of Electroceramics》2006,17(2-4):387-391
BaTi4O9 thin films were grown on a Pt/Ti/SiO2/Si substrate using RF magnetron sputtering. A homogeneous BaTi4O9 crystalline phase developed in the films deposited at 550∘C and annealed above 850∘C. When the thickness of the film was reduced, the capacitance density and leakage current density increased. Furthermore,
the dielectric constant was observed to decrease with decreasing film thickness. The BaTi4O9 film with a thickness of 62 nm exhibited excellent dielectric and electrical properties, with a capacitance density of 4.612
fF/μm2 and a dissipation factor of 0.26% at 100 kHz. Similar results were also obtained in the RF frequency range (1–6 GHz). A low
leakage current density of 1.0 × 10−9 A/cm2 was achieved at ± 2 V, as well as small voltage and temperature coefficients of capacitance of 40.05 ppm/V2 and –92.157 ppm/∘C, respectively, at 100 kHz. 相似文献
7.
ZnGa2O4 thin film phosphors have been synthesized on ITO coated glass and soda-lime glass at a firing temperature of 500∘C and an annealing temperature of 500∘C and 600∘C via a chemical solution method using Zinc acetate dihydrate, Gallium nitrate hydrate and 2-methoxiethanol as a solution.
XRD patterns of the film phosphors synthesized showed the peaks of ZnGa2O4 crystalline phases. AFM surface morphologies of the ZnGa2O4 thin film phosphors revealed marked differences according to an annealing temperature of 500∘C and 600∘C under an annealing atmosphere (3% H2/Ar). On the other hand, the sheet resistance of ZnGa2O4 thin film phosphors, which were measured by four-point probe instrument, was approximately 5.76 Ω /square and 7.86 Ω /square
with annealing temperature, respectively. The ZnGa2O4 thin film phosphors exhibited blue emission spectra with peak wavelength of 434 nm and 436 nm by ultra-violet excitation
around 230 nm. 相似文献
8.
P-type thermoelectric Bi0.5Sb1.5Te3 compounds were prepared by the spark plasma sintering method with temperature ranges of 300–420∘C and powder sizes of ∼75 μm, 76–150 μm, 151–250 μm. As the sintering temperature increased, the electrical resistivity and
thermal conductivity of the compound were greatly changed due to an increase in the relative density. The Seebeck coefficient
and electrical resistivity were varied largely with decreasing the powder size. Subsequently, the compound sintered at 380∘C with the powders of ∼75 μm showed the maximum figure-of-merit of 2.65 × 10−3K−1 and the bending strength of 73 MPa. 相似文献
9.
Ultrathin HfO2 gate dielectrics have been deposited on strained Si0.69Ge0.3C0.01 layers by rf magnetron sputtering. The polycrystalline HfO2 film with a physical thickness of ∼6.5 nm and an amorphous interfacial layer with a physical thickness of ∼2.5 nm have been
observed by high resolution transmission electron microscopy (HRTEM). The electrical properties have been studied using metal-oxide-semiconductor
(MOS) structures. The fabricated MOS capacitors on Si0.69 Ge0.3C0.01 show an equivalent oxide thickness (EOT) of 2.9 nm, with a low leakage current density of ∼4.5 × 10 − 7 A/cm2 at a gate voltage of –1.0 V. The fixed oxide charge and interface state densities are calculated to be 1.9 × 1012 cm− 2 and 3.3 × 10 11 cm− 2eV−1, respectively. The temperature dependent gate leakage characteristics has been studied to establish the current transport
mechanism in high-k HfO2 gate dielectric to be Poole–Frenkel one. An improvement in electrical properties of HfO2 gate dielectrics has been observed after post deposition annealing in O2 and N2 environments. 相似文献
10.
I. H. Kim D. Y. Ku J. H. Ko D. Kim K. S. Lee J.-h. Jeong T. S. Lee B. Cheong Y.-J. Baik W. M. Kim 《Journal of Electroceramics》2006,17(2-4):241-245
To improve the stability of sputter-deposited ZnO:Al (AZO) films at high temperature above 300∘C, an amorphous Zn-Sn-O (ZTO) film was deposited on the top of AZO films as an protective layer by co-sputtering of pure ZnO
and SnO2 targets. Amorphous ZTO films had resistivity in the range from 10−2 to 10−3 Ωcm and were stable up to temperature of 400∘C. Heat treatments of bare AZO films in the atmosphere at 400∘C resulted in a dramatic increase in the resistivity accompanied by substantial decrease in carrier concentration and Hall
mobility. The AZO films covered with the ZTO film showed remarkable improvement in thermal stability for subsequent heat treatments
in the temperature range from 200 to 400∘C in the atmosphere as well as chemical stability in weak acidic solution. X-ray photoelectron spectroscopy analysis showed
that the improvement was attained by ZTO layer acting as diffusion barrier of oxygens and/or water vapors. 相似文献
11.
Wei-Kuo Chia Ying-Chung Chen Cheng-Fu Yang San-Lin Young Wang-Ta Chiang Yu-Tarng Tsai 《Journal of Electroceramics》2006,17(2-4):173-177
Bi4Ti3O12 thin films are deposited on ITO/glass and Pt/Ti/Si(100) substrates by R.F. magnetron sputtering at room temperature. The
films are then heated by a rapid thermal annealing (RTA) process conducted in oxygen atmosphere at temperatures ranging from
550–700∘C. X-ray diffraction examination reveals that the crystalinity of the films grown on Pt/Ti/Si is better than that of the films
grown on ITO/glass under the same fabrication conditions. SEM observation shows that the films grown on Pt/Ti/Si are denser
than those grown on ITO/glass substrates. Interactive diffusion between the Bi4Ti3O12 film and the ITO film increases with the increase of annealing temperature. The optical transmittance of the thin film annealed
at 650∘C is found to be almost 100% when the effect of the ITO film is excluded. The relative dielectric constants, leakage currents
and polarization characteristics of the two films are compared and discussed. 相似文献
12.
Wataru Sakamoto Yu-ki Mizutani Naoya Iizawa Toshinobu Yogo Takashi Hayashi Shin-ichi Hirano 《Journal of Electroceramics》2006,17(2-4):293-297
Ferroelectric Si-doped (Bi,Nd)4Ti3O12 thin films have been prepared on Pt/TiOx/SiO2/Si substrates through metal-organic compounds by the chemical solution deposition. The Bi3.25Nd0.75Ti2.9Si0.1O12 (BNTS) precursor films were found to crystallize into the Bi-layered perovskite Bi4Ti3O12 single-phase above 600∘C. The synthesized BNTS films revealed a random orientation having a strong 117 reflection. The BNTS thin films prepared between
600∘C and 700∘C showed well-saturated P-E hysteresis loops with P
r of 13–14 μ C/cm2 and E
c of 100–110 kV/cm at an applied voltage of 5 V. The surface roughness of the BNTS thin films was improved by Si doping compared
with that of undoped Bi3.35Nd0.75Ti3O12 films. 相似文献
13.
Jong-Hee Kim Dong-Hyun Peck Rak-Hyun Song Gil-Young Lee Dong-Ryul Shin Sang-Hoon Hyun Jürgen Wackerl Klaus Hilpert 《Journal of Electroceramics》2006,17(2-4):729-733
Synthesis and sintering properties of the (La0.8Ca0.2−x
Sr
x
)CrO3 samples doped by two alkaline earth metals in comparison to the doped only by one alkaline earth metal were evaluated by
phase analysis, sintering properties, thermal expansion behaviors, and electrical conductivity. The sintered (La0.8Ca0.2−x
Sr
x
)CrO3 (x = 0, 0.05, and 0.1) and (La0.8Ca0.2−x
Sr
x
)CrO3 (x = 0.2) were found to have orthorhombic and rhombohedral symmetries, respectively. Relative density of the (La0.8Sr0.2)CrO3 sample sintered at 1500∘C for 5 h was lower than that of the (La0.8Ca0.2−x
Sr
x
)CrO3 (x = 0, 0.05, and 0.1) sample. TECs of the (La0.8Ca0.2−x
Sr
x
)CrO3 (x = 0, 0.05, 0.1, and 0.2) in air were 11 × 10−6/∘C, 11.2 × 10−6/∘C, 11.2 × 10−6/∘C, and 11.3 × 10−6/∘C, respectively. The electric conductivity of the (La0.8Ca0.2−x
Sr
x
)CrO3 sample was determined. 相似文献
14.
Monazite-type compounds, BiPO4 polymorphs were prepared by the solid-state reaction method. The phase transformation and microwave dielectric properties
of sintered ceramics were investigated using the X-ray powder diffraction (XRD) and a network analyzer, respectively. The
low-temperature phase of BiPO4 has monoclinic structure, and was transformed into the high-temperature phase with a slight distortion of monoclinic when
it is heated above 600∘C. The effect of the transformation on the microwave dielectric properties was examined. It was found that the dielectric
properties of each phase were significantly different. In particular, the high-temperature phase sintered at 950∘C has good microwave dielectric properties; the relative dielectric constant (ε
r
) = 22, the quality factor (Q× f) = 32,500 GHz and the temperature coefficient of resonant frequency (τ
f
) = − 79 ppm/ ∘C. 相似文献
15.
Fransiska Cecilia Kartawidjaja Zhaohui Zhou John Wang 《Journal of Electroceramics》2006,16(4):425-430
Heterolayered Pb(Zr1 − x
Ti
x
)O3 thin films consisting of alternating PbZr0.7Ti0.3O3 and PbZr0.3Ti0.7O3 layers were successfully deposited via a multistep sol-gel route assisted by spin-coating. These heterolayered PZT films,
when annealed at a temperature in the range of 600–700∘C show (001)/(100) preferred orientation, demonstrate desired ferroelectric and dielectric properties. The most interesting
ferroelectric and dielectric properties were obtained from the six-layered PZT thin film annealed at 650∘C, which exhibits a remanent polarization of 47.7 μC/cm2 and a dielectric permittivity of 1002 at 100 Hz. Reversible polarization constituents a considerably high contribution towards
the ferroelectric hysteresis of the heterolayered PZT films, as shown by studies obtained from C-V and AC measurement. 相似文献
16.
Yi Wang Lei Sun Ling-Gang Kong Jin-Feng Kang Xing Zhang Ru-Qi Han 《Journal of Electroceramics》2006,16(4):389-391
Effects of Co
x
Ti
1−x
O
2−δ on the sinterability and the ferromagnetism properties of Co
2sO
3/TiO
2 (0.0 < x < 0.06) ceramics are investigated in this paper. It is found that the Co-doped Ti
O
2 ceramics transform from paramagnetism to room-temperature ferromagnetism (RTFM) after hydrogenation. With annealing temperatures
at 600∘
C and 1000∘
C, these as-prepared samples present anatase and rutile structures respectively, which are analyzed with X-ray diffraction
(XRD). After hydrogenation, the relation between temperature variations and the magnetic susceptibility for the hydrogenated
samples were measured under zero-field-cooled and field-cooled conditions by using SQUID magnetometer. And the hysteresis
loops are observed. These ferromagnetism resonance data suggest that the observed RTFM is at least partly due to the Cobalt
nano-particles in our hydrogenated samples. 相似文献
17.
Hyun-Suk Kim Il-Doo Kim Ki-Byoung Kim Tae-Soon Yun Jong-Chul Lee Harry L. Tuller Won-Youl Choi Ho-Gi Kim 《Journal of Electroceramics》2006,17(2-4):421-425
We report on high tunablity of Ba0.6Sr0.4TiO3 (BST) thin films realized through the use of atomic layer deposited TiO2 films as a microwave buffer layer between BST and a high resistivity (HR) Si substrate. Coplanar waveguide (CPW) meander-line
phase shifters using BST/TiO2/HR-Si and BST/MgO structures exhibited a differential phase shift of 95∘ and 24.4∘, respectively, at 15 GHz under an electric field of 10 kV/cm. The figure of merit of the phase shifters at 15 GHz was 30.6∘/dB for BST film grown on a TiO2/HR-Si substrate and 12.2∘/dB for BST film grown on a MgO single crystal substrate. These results constitute significant progress in integrating BST
films with conventional silicon technology. 相似文献
18.
Seung-Kyu Choi Jae-Min Jang Sung-Hak Yi Jung-A Kim Woo-Gwang Jung 《Journal of Electroceramics》2009,23(2-4):180-184
The influence of ion beam bombardment on sapphire substrate was investigated on the electrical and optical characteristics of Indium–Gallium–Nitride/Gallium–Nitride (InGaN/GaN) single quantum well (SQW) structure. Ion bombardment of N+, He+, H+ ions were made on single crystal substrate of sapphire with dose of 1?×?1014–17 ions/cm2. The InGaN/GaN SQW was fabricated on the ion beam bombarded sapphire substrate in two-flow Metal Organic Chemical Vapor Deposition (MOCVD) equipment. The thickness of InGaN/GaN SQW was about 20 nm and the composition of InGaN/GaN SQW was found to be In0.1Ga0.9N. In PL spectra, it is found that InGaN/GaN SQW was emitted from 441.1 to 446.6 nm (2.8–2.7 eV). The highest mobility value of 118 cm2/V–S and the lowest carrier concentration of 3.41?×?1017/cm2 was found for N of 1016 ions/cm2 ion beam bombarded sample. The optimal condition for InGaN/GaN SQW on sapphire substrate of ion beam bombardment was deduced to be N+ ion dose of 1016 ions/cm2. 相似文献
19.
Jong-Yoon Ha Ji-Won Choi Chong-Yun Kang Seok-Jin Yoon Doo Jin Choi Hyun-Jai Kim 《Journal of Electroceramics》2006,17(2-4):399-403
The effect of the addition of glass on the densification, low temperature sintering, and microwave dielectric properties of
the Ca[(Li1/3Nb2/3)1−x
Tix]O3−δ(CLNT) was investigated. Addition of glass (B2O3-ZnO-SiO2-PbO system) improved the densification and reduced the sintering temperature from 1150∘C to 900∘C of Ca[(Li1/3Nb2/3)1−x
-Tix]O3−δ microwave dielectric ceramics. As increasing glass contents from 10 wt% to 15 wt%, the dielectric constants (εr) and bulk density were increased. The quality factor (Q⋅f0), however, was decreased slightly. The temperature coefficients of the resonant frequency (τf) shifted positive value as increasing glass contents over Ti content is 0.2 mol. The dielectric properties of Ca[(Li1/3Nb2/3)0.75Ti0.25]O3−δ with 10 wt% glass sintered at 900∘C for 3 h were εr = 40 Q·f0 = 11500 GHz, τf = 8, ppm/°C. The relationship between the microstructure and dielectric properties of ceramics was studied by X-ray diffraction
(XRD), and scanning electron microscope (SEM). 相似文献
20.
M.-S. Yoon Y.-M. Kim S.-Y. Kweon T.-W. Hong Y.-G. Lee S.-L. Ryu I.-H. Kim H.-J. Kim S.-C. Ur 《Journal of Electroceramics》2006,17(2-4):635-637
Perovskite-types 0.05Pb(Mn1/3Sb2/3)O2-0.95Pb- (Zr0.5Ti0.5)O3 (PMS-PZT) was synthesized by conventional bulk ceramic processing technique. ZnO as a dopant up to 0.5 mol% was incorporated
into the PMS-PZT system, and the effects on piezoelectric properties were investigated. Pyrochlore phase was not detected
to form during the synthesis of the PMS-PZT system with 0–0.5 mol% ZnO addition. The highest density of 7.92 g/cm3 was obtained when sintered at 1200∘C for 2 h. Piezoelectric properties as a function of ZnO content were evaluated using a gain phase analyzer. Piezoelectric
charge constant (d
31) and piezoelectric voltage output coefficient (g
31) increased up to −130 pC/N and −24.9 × 103Vm/N, respectively, with increasing ZnO content. Mechanical quality factor (Q
m) was shown to reduce considerably with increasing ZnO content. When 0.3 mol% of ZnO was added into the system, electromechanical
coupling factor (k
p) and relative dielectric constant (ε33
T
/εo) reached to the maximum of 56% and 1727, respectively. 相似文献