• 한국전기전자재료학회논문지
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• 제23권10호
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• pp.747-751
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• 2010

In the study, the characteristics of the etched Zinc oxide (ZnO) thin films surface, the etch rate of ZnO thin film in $Cl_2/BCl_3/Ar$ plasma was investigated. The maximum ZnO etch rate of 53 nm/min was obtained for $Cl_2/BCl_3/Ar$=3:16:4 sccm gas mixture. According to the x-ray diffraction (XRD) and atomic force microscopy (AFM), the etched ZnO thin film was investigated to the chemical reaction of the ZnO surface in $Cl_2/BCl_3/Ar$ plasma. The field emission auger electron spectroscopy (FE-AES) analysis showed an elemental analysis from the etched surfaces. According to the etching time, the ZnO thin film of etched was obtained to The AES depth-profile analysis. We used to atomic force microscopy to determine the roughness of the surface. So, the root mean square of ZnO thin film was 17.02 in $Cl_2/BCl_3/Ar$ plasma. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the plasmas.

• 통합자연과학논문집
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• 제5권4호
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• pp.233-236
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• 2012

In this study, PEDOT thin films polymerized with Iron(III)tosylate ($Fe(PTS)_3$) and grown on acetic acid-catalyzed 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM) surfaces by VPP method have been investigated. PEDOT thin films were synthesized on APS self-assembled $SiO_2$ wafer surface at two different concentrations (20 wt% and 40 wt%) and growth time (3 and 30 minutes), and then they were compared. PEDOT vapour phase-polymerized with 40 wt% $Fe(PTS)_3$ oxidant completely formed a thin film on acetic acid-catalyzed APS-SAM surface while with 20 wt% $Fe(PTS)_3$ did not at all. It means that the oxidant can be uniformly coated on acetic acid-catalyzed APS-SAM surface at the 40 wt% concentration, which gives rise to the uniform growth of PEDOT thin film on it.

• 한국세라믹학회지
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• 제43권2호
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• pp.74-78
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• 2006

A non-integrated type noise filter on a Coplanar Waveguide (CPW) transmission line is demonstrated by using a highly resistive $Co_{41}Fe_{38}Al_{13}O_8$ nanogranular thin film with the dimensions of $4\;mm (\iota)\times4\;mm(\omega)\times0.1\;{\mu}m(t)$. The noise suppression characteristics are evaluated without placing an insulating layer between the CPW line and the magnetic thin film. The insertion loss is very low being less than 0.3 dB and this low value is maintained up to 2 GHz. At a ferromagnetic resonance frequency of 3.3 GHz, the power loss is very large and the degree of noise attenuation is measured to be 3 dB. This level of noise attenuation is still small for real applications; however, considering the small magnetic volume used in this work, further improvement is expected by simply increasing the magnetic volume and by integrating the magnetic thin film into the CPW transmission line.

• 한국자기학회지
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• 제21권3호
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• pp.88-92
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• 2011

Pulsed Laser Deposition 방법을 사용하여 $Zn_{0.4}Fe_{2.6}O_4$ 박막을 증착하였으며 이의 결정성 및 자기적 특성을 증착온도의 함수로 조사하였다. 증착온도가 $300^{\circ}C$었을 경우 박막은 코런돔(corundom) ${\alpha}-$Fe_2O_3$ 또는 워자이트(wurzite) ZnO 구조를 지니고 있었으나 증착온도가 $500^{\circ}C$로 증가되었을 경우에는 $Zn_{0.4}Fe_{2.6}O_4(111)/Al_2O_3(0001)$의 결정 방향을 지닌 매우 안정된 역스피넬(inverse spinel) 성장이 이루어졌으며 또한 표면의 거칠기도 증착온도가 $300^{\circ}C$ 일 때 보다 더 평평하여졌다. 이러한 역스피넬 $Zn_{0.4}Fe_{2.6_O_4$ 박막에서는 X-선 산란 분석 결과 ${\alpha}-$Fe_2O_3$, ZnO에 해당하는 픽들은 전혀 관측되지 않았으며 이러한 사실들은 Zn가 증착온도를 높여줌에 따라 역스피넬의 사면체 자리에 치환되었음을 의미한다. M-H 곡선의 측정 결과 증착온도 $300^{\circ}C$ 박막은 자성 특성이 거의 관측되지 않은 반면 $500^{\circ}C$ 박막의 경우에는 매우 뚜렷한 강자성 특성을 확인할 수 있었으며 벌크보다 작은 포화자화 값은 팔면체 자리의 Fe 스핀들의 삐뚤림(canting)에 의한 것으로 이해된다.

• Journal of Magnetics
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• 제14권4호
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• pp.161-164
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• 2009

Iron-doped $Sn_{1-x}Fe_xO_2$ (x = 0.0, 0.05, 0.1, 0.2, 0.33) thin films on Si(100) substrates and powders were prepared by a chemical solution process. The x-ray diffraction (XRD) patterns of the $Sn_{1-x}Fe_xO_2$ thin films and powders showed a polycrystalline rutile tetragonal structure. Thermo gravimetric (TG) - differential thermal analysis (DTA) showed the final weight loss above $430{^{\circ}C}$ for all powder samples. According to XRD Rietveld refinement of the powders, the lattice parameters and unit cell volume decreased with increasing Fe content. The magnetic properties were characterized using a vibrating sample magnetometer (VSM) and M$\ddot{o}$ssbauer spectroscopy. The thin film samples with x = 0.1 and 0.2 showed paramagnetic properties but thin films with x = 0.33 exhibited ferromagnetic properties at room temperature. Mossbauer studies revealed the $Fe^{3+}$ valence state in the samples. The ferromagnetism in the samples can be interpreted in terms of the direct ferromagnetic coupling of ferric ions via an electron trapped in a bridging oxygen deficiency, which can be explained using the F-center exchange model.

• 한국표면공학회지
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• 제15권1호
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• pp.11-18
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• 1982

80% Ni-Permalloy is soft magnetic material with high initial permeability and low magnetic coercive force Hc, and is used to computer memory cores and minirelays of communication e-ngineering. In this paper 80 Permalloy thin film on copper cathode was alloy-deposited from Watts so-lution contatining FeSO4$.$7H2O. The amount of FeSO4$.$7H2O in the solution, pH, temperature of the solution and plating current density were varied as parameters and the resulting comp-osition changes of deposited film were analyzed electrochemically with respect to the parame-ters. From the above procedure electroplating conditions for deposition of 80 Permalloy were est-ablished as following: 17-21 g/$\ell$ of FeSO4$.$7H2O in Watts solution, current density 1.0-2.0 Amp/dm2, pH 2.5-3.0 and temperature range of 50-60$^{\circ}C$.

• 분석과학
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• 제8권4호
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• pp.669-674
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• 1995

The preparation and characterization of photosemiconductive electrodes of GaAs and of $Fe_2O_3$ doped with MgO or CaO were investigated. The doped $Fe_2O_3$ photosemiconductive electrodes were prepared from thin films sintered at temperatures from 1,100 to $1,450^{\circ}C$, and rapidly quenched in distilled water. The surfaces of the electrodes containing both corundum structure of $Fe_2O_3$ and spinel structure of $Mg_xFe_{3-x}O_4$ or $Ca_xFe_{3-x}O_4$ were analyzed by X-ray diffraction and scanning electron microscopy. The cathodic and anodic photocurrents on these electrodes indicated a critical doping amount of 5-11 wt. %. The photocurrents were enhanced when GaAs electrodes were treated with methylene violet the anodic photo-currents were temporarial enhanced and changed to the cathodic ptotocurrents after the surface was dryed.

• 한국전기전자재료학회논문지
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• 제31권4호
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• pp.226-230
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• 2018

Pure $BiFeO_3$ (BFO) and codoped $Bi_{0.9}A_{0.1}Fe_{0.975}Zn_{0.025}O_{3-{\delta}}$ (A=Eu, Dy) thin films were prepared on Pt(111)/Ti/$SiO_2$/Si(100) substrates by chemical solution deposition. The remnant polarizations (2Pr) of the $Bi_{0.9}Eu_{0.1}Fe_{0.975}Zn_{0.025}O_{3-{\delta}}$ (BEFZO) and $Bi_{0.9}Dy_{0.1}Fe_{0.975}Zn_{0.025}O_{3-{\delta}}$ (BDFZO) thin films were about 36 and $26{\mu}C/cm^2$ at the maximum electric fields of 900 and 917 kV/cm, respectively, at 1 kHz. The codoped BEFZO and BDFZO thin films showed improved electrical properties, and leakage current densities of 3.68 and $1.21{\times}10^{-6}A/cm^2$, respectively, which were three orders of magnitude lower than that of the pure BFO film, at 100 kV/cm.

• The Korean Journal of Ceramics
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• 제4권3호
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• pp.249-253
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• 1998

The influence of PbO additive on dielectric properties and sintering behavior of $(Pb_{0.46}Ca_{0.55})$ {$(Fe__1/2}Nb_{1/2}){0.9}Sn_{{0.1}$}$O_3$ ceramics has been investigated. The incorporation of a limited excess PbO ($\leq$2.0 wt. %) in the starting materials is quite beneficial for densification in the temperature range of 1150~$1175^{\circ}C$ in air. At a small doping level (0.8 wt. %) the ceramics prepared from powders calcined at $900^{\circ}C$ showed the best dielectric properties. The dielectric constants ($\varepsilon_r$) and Q.f were found to be 85.8~85.6 and 8530~8600 GHz, respectively. The temperature coefficient of resonant frequency ($\tau_f$) varied in the range of -2~4 $ppm/^{\circ}C$. Examination of the microstructure as well as analysis of the second phases in these materials revealed the presence of the pyrochlore-type phase which is detrimental to the dielectrics.

• Transactions on Electrical and Electronic Materials
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• 제16권1호
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• pp.1-4
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• 2015

(111)-oriented and random oriented $Pb_{0.8}Ba_{0.2}ZrO_3$ (PBZ) perovskite relaxor ferroelectric thin films were fabricated on Pt(111)/$TiO_x$/$SiO_2$/Si substrate by sol-gel method. Nano-scaled antiferroelectric and ferroelectric two-phase coexisted in both (111)-oriented and random oriented PBZ thin film. High dielectric tunability (${\eta}=75%$, E = 560 kV/cm) and figure-of-merit (FOM ~ 236) at room temperature was obtained in (111)-oriented thin film. Meanwhile, giant electrocaloric effect (ECE) (${\Delta}T=45.3K$ and ${\Delta}S=46.9JK^{-1}kg^{-1}$ at $598kVcm^{-1}$) at room temperature (290 K), rather than at its Curie temperature (408 K), was observed in random oriented $Pb_{0.8}Ba_{0.2}ZrO_3$ (PBZ) thin film, which makes it a promising material for the application to cooling systems near room temperature. The giant ECE as well as high dielectric tunability are attributed to the coexistence of AFE and FE phases and field-induced nano-scaled AFE to FE phase transition.