巻号一覧
49 巻, 2 号
選択された号の論文の15件中1～15を表示しています
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Mechano-chemical Synthesis of RbAg4I5 and KAg4I5 Crystals and Their Silver lon Conducting PropertiesHuifen Peng, Nobuya Machida, Toshihiko Shigematsu2002 年 49 巻 2 号 p. 69-74
発行日: 2002/02/15
公開日: 2009/12/04
ジャーナル フリーA high-energy-ball-milling process was applied to the synthesis of the RbAg4I5 and KAg4I5 crystalline phases, which were known to show high Ag+ ion conductivity 2.7×101 Sm-1 at room temperature. RbI, KI, and AgI were used as raw materials for the mechanical synthesis of the RbAg4I5 and KAg4I5 phases. Only 20min-ball milling of a mixture of RbI and AgI led to the formation of RbAg4I5 phase, and the powder sample after 140 min-ball milling was containing only RbAg4I5 phase. On the other hand, the preparation of the sample containing only KAg4I5 phase needed the ball-mill treatment more than 50h.The obtained RbAg4I5 and KAg4I5 samples showed high ion conductivity more than 101 Sm-1 at room temperature, and the conductivities were almost same as those of the RbAg4I5 and KAg4I5 crystalline phases reported by Owens et al. The DC polarization measurements suggested that main carrier of the ball-milled samples was silver ions and the silver ion transport numbers of the ball-milled samples were almost unity.抄録全体を表示PDF形式でダウンロード (443K) -
山崎 陽太郎2002 年 49 巻 2 号 p. 76
発行日: 2002/02/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (100K) -
中野 敦之, 鈴木 孝志, 桃井 博2002 年 49 巻 2 号 p. 77-86
発行日: 2002/02/15
公開日: 2009/05/22
ジャーナル フリーThe incessant demand for higher density circuits in electronics has required the continued miniaturization of all components. As a solution, surface mount technology (SMT) was developed resulting in densification of component mounting. Therefore, efforts have been made to produce electronic components in surface mount device (SMD) form. Since the inductor had to be wound with wire, it was difficult to reduce the size of the chip without any deterioration of magnetic properties. Thick-film printing process and low temperature sintering NiCuZn ferrites due to its co-firability with Ag (below 900°C) were developed for multilayer chip inductors in 1980. It is known that NiZn ferrite has high resistance, and that CuZn ferrite is a low-fire composition, therefore NiCuZn ferrite was studied to combine both properties. Over the past decades a considerable number of studies have been made on the interface between Ag-conductor and ferrite, Ag-diffusion with specially reference to the micro/nano structure and electromagnetic properties of NiCuZn ferrite. Therefore, it was known that the controlling stress by the internal Ag-conductor and CuO1-x/Ag on ferrites grain boundary is most important key point for high performance multilayer chip ferrites as well as the chemical composition of ferrite.抄録全体を表示PDF形式でダウンロード (6549K) -
阿部 正紀2002 年 49 巻 2 号 p. 87-94
発行日: 2002/02/15
公開日: 2010/11/19
ジャーナル フリーPolycrystallite fine particles and thin films of spinel ferrites ((Fe, M)3O4, M=Fe, Co, Ni, Mn, Zn, Ti, etc.) are synthesized directly from an aqueous solution at 3-100°C, utilizing Fe2+→Fe3+ oxidation. This low temperature process allows us to fabricate new ferrite film devices on substrates of such non-heat-resistant materials as plastics. It also allows us to immobilize bio-active molecules directly onto the surfaces of ferrite fine particles during their synthesis, which is promising for biomedical device applications. The fine particles and thin films, though prepared at the low temperatures, have saturation magnetization of magnitude favorably compared to that observed for bulk ferrite samples. The principle of the aqueous synthesis of ferrite is described.抄録全体を表示PDF形式でダウンロード (3565K) -
藤田 裕子, 松永 達也, 加藤 千晴, 鴻池 健弘, 伴野 国三郎2002 年 49 巻 2 号 p. 95-99
発行日: 2002/02/15
公開日: 2009/12/04
ジャーナル フリーCo-firing of YIG and conductors enables miniaturized, broadband isolators. The problem is that the conductors are melted in the co-fired body because firing temperatures of YIG are generally higher than the melting points of highly conductive metals like Ag. We have focused on Au as the conductor because it has the highest melting point among highly conductive metals. Then we have tried to reduce firing temperature of YIG by Cu-substitution. When a was 0.05 in (Ca2xY3-2x)(Fe5-x-y-z-2αVxAlyIn2CuαZrα)O12, the YIG was able to be fired at 1020°C, lower than melting point of Au (1064°C), with narrow ferromagnetic resonance as ΔH=33Oe. Accordingly it is achieved that sintering temperature is reduced by 60°C compared to the YIG at α=0. It is thought that Cu segregates at grain boundary, when α is larger than 0.05.抄録全体を表示PDF形式でダウンロード (3175K) -
松尾 良夫, 橋本 敏隆, 中尾 文昭, 渡辺 武司2002 年 49 巻 2 号 p. 100-107
発行日: 2002/02/15
公開日: 2009/05/22
ジャーナル フリーLake Hamana situated near Mt. Fuji is a popular tourist spot attracting particularly an increasing number of marine sportspeople in recent years. With the active tourism and commercial development, however, the lake environment is burdened by accumulating sludge. In the present study, we attempted for recycling purposes to develop a new electronic material by mixing lake sludge with a Mn-Zn ferrite powder. The effects of mixing ratios and heat treatment conditions on the magnetic properties and microstructures of sintered samples were investigated. As a result, we found it possible to use such mixtures as composite materials for producing electromagnetic radiation absorbers with superior properties. Thus, we found that the magnetic characteristics of lake sludge mixed with a Mn-Zn ferrite powder are easily controllable. By optimizing various conditions, we should be able to apply lake sludge and ferrite powder mixtures to the manufacture of EMC and other magnetic devices.抄録全体を表示PDF形式でダウンロード (4515K) -
岡 裕子, 柿崎 浩一, 平塚 信之2002 年 49 巻 2 号 p. 108-113
発行日: 2002/02/15
公開日: 2009/05/22
ジャーナル フリーManganese zinc ferrite thin films were prepared on quartz substrates buffered by a (00l) oriented ZnO underlayer by conventional rf magnetron sputtering method Mn-Zn-Fe oxide layers deposited on the ZnO underlayers were annealed in various atmospheres at 800°C for 5hours. When the films were annealed either at reduced pressure in air or in N2 gas flow, single phase spinel-type ferrite was formed. Manganese zinc ferrite films annealed in N2 gas flow had excellent soft magnetic characteristics compared with the films annealed at reduced pressure in air because of their remarkable grain growth. Furthermore, Bi2O3 and V2O5 were added for the purpose of inducing crystal grain growth. Manganese zinc ferrite films with Bi2O3 were improved in their saturation magnetization because of their grain growth and good crystallinity. On the other hand, manganese zinc ferrite films with V2O5 showed excellent soft magnetic characteristics, when vanadium of 0.51 at.% was added.抄録全体を表示PDF形式でダウンロード (6622K) -
木村 修, 村上 佳隆, 松本 雅史, 坂倉 光男, 荘司 和男2002 年 49 巻 2 号 p. 114-119
発行日: 2002/02/15
公開日: 2010/07/12
ジャーナル フリーMagnetic properties were studied for magnetoplumbite type ferrites, namely, Z, W or Y type hexagonal ferrites, whose basal planes contain the easy direction of magnetization. Increase in the degree of crystal orientation of these ferrite is known as an effective method to enhance their permeabilities. Hence, a hot-forging process in air was adopted to align the basal planes of the crystallites of the ferrites perpendicular to the hot-forging axis. The degrees of crystal orientation of the hot-forged samples were determined by XRD according to the Lotgerings' definition. It was found that the permeabilities and the degrees of the crystal orientation of the hot-forged samples increased with increasing hot-forging temperature.抄録全体を表示PDF形式でダウンロード (1634K) -
青木 卓也, 村瀬 琢, 野村 武史2002 年 49 巻 2 号 p. 120-123
発行日: 2002/02/15
公開日: 2009/12/04
ジャーナル フリーFerric oxide, that is a principal raw material of ferrite, contains anions as impurities. Since it is generally produced from iron chloride or iron sulfate solution obtained from waste liquid of acid cleaning. In this paper, the effects of anions on sintering behavior of NiCuZn ferrite were investigated. The sintered densities of NiCuZn ferrites were not effected by the addition of anions. However the beginning temperatures of shrinkage were slightly shifted to higher temperature. The diffusion mechanism at initial stage of sintering changed from grain boundary diffusion to bulk diffusion by the addition of anions. Reaction products of CuO and anions could change the diffusion mechanism.抄録全体を表示PDF形式でダウンロード (298K) -
遠藤 真視, 中野 敦之2002 年 49 巻 2 号 p. 124-128
発行日: 2002/02/15
公開日: 2009/05/22
ジャーナル フリーHigher frequency adaptability has been required for electronic devices. It is well known that Z-type hexagonal ferrites can be used at higher frequency range compared by spinel-type ferrites. Then we applied hexagonal ferrites to multilayer chip inductors with Ag electrodes. Bi2O3 and CuO were added in order to lower the firing temperature. Bi2O3 segregated at grain boundaries and CuO mainly existed inside grains that was confirmed by TEM-EDX observation. The 1608 chip-inductors were made with the low firing temperature Z-type ferrites and they showed the XR cross point of 1.4 GHz.抄録全体を表示PDF形式でダウンロード (4363K) -
橘 武司, 泉 健二, 川井 淳史, 加納 正孝, 中川 貴, 山本 孝夫, 島田 武司, 川野 眞治2002 年 49 巻 2 号 p. 129-134
発行日: 2002/02/15
公開日: 2010/07/12
ジャーナル フリーConditions for synthesizing single phase materials of the hexagonal Z-type were investigated by preparing samples with various compositions (x=0, 0.2, 0.4, 0.6 in Ba3Co2-xFe24+xO41) and oxygen partial pressures, PO2=21.3, 31.3, 41.3, 61.3, 101.3 kPa, at T=1573 K. The phases formed in the samples were examined by X-ray diffraction technique and the dc magnetization was measured as a function of temperature by a vibrating sample magnetometer (VSM) at a magnetic field of 5.6 kA/m. The correlation between the phases occurring in the samples and the complex permeability μ, at 100MHz was investigated, and it was indicated that high μr is obtained when the hexagonal Z-type occurs without any other phase. The highest μr=20 was obtained with conditions of x =0.2, PO2=101.3 at 1573 K. The neutron diffraction patterns were measured between 294 and 773 for the sample of x=0.4. Two significant magnetic Bragg reflections were observed in the pattern measured at 294 K, but no peak at 773 K. Integrated intensities of the magnetic scattering peaks were plotted against temperatures, which was consistent with the magnetization vs. temperature curve measured with VSM. It was indicated that the hexagonal Z-type phase exhibits two stage magnetic transition at 500-540 and 680 K.抄録全体を表示PDF形式でダウンロード (414K) -
佐々木 英明, Oscar Juan Perales Perez, Balachandran Jeyadevan, 田路 和幸, 粕谷 厚 ...2002 年 49 巻 2 号 p. 135-140
発行日: 2002/02/15
公開日: 2009/05/22
ジャーナル フリーWe propose two methods for the size selection at nanometer level based on manipulation of the surface interaction between particles. The control over the particle interaction has been achieved by modulating the interparticle distances through: (a) coating the nanometer size particles with anionic surfactants having different chain lengths, and (b) introducing polar solvents to suspensions in non-polar solvents dispersing nanometer size particles coated with sodium oleate. An effective size selection of nanometer size magnetite particles has been achieved using both of these methods and the results are presented here. Depending on the conditions, stable suspensions of nearly monodispersed magnetite nanoparticles less than 10 nm in diameter with a standard deviation below 0.2 were obtained from polydispersed powder less than 40nm in diameter and 0.6 in standard deviation. The size selection was confirmed by using the TEM measurements of separated fractions., The magnetic measurements of these size classified samples were carried out in zero field cooled (ZFC) and field cooled (FC) conditions. The relation between particle size and blocking temperature conformed to theoretical predictions and also confirmed the success of the selection methods. Furthermore, the field-cooled measurements of separated fractions suggested that the influence of surface spins to magnetic properties of the particle become considerable when the particle diameter is below 6nm.抄録全体を表示PDF形式でダウンロード (3804K) -
小野 秀昭, 田湯 哲朗, 脇 憲尚, 杉山 龍男, 島田 宗勝, 加納 眞, 藤木 章, 山元 洋, 高杉 圭祐, 谷 雅人2002 年 49 巻 2 号 p. 141-145
発行日: 2002/02/15
公開日: 2009/05/22
ジャーナル フリーMagnetic properties and structures of low rare-earth content (Nd=2-7at.%) α-Fe/Nd2e14B type Nd-Fe-Co-V-B system bulk exchange-spring magnets prepared by the Spark Plasma Sintering (SPS) method were investigated. In this range of Nd content, the bulk magnets showed the same magnetic properties as those of the annealed ribbons used as the raw materials. The saturation magnetization and soft/hard phase ratio corresponded with the estimated values. However, the exchange coupling strength decreased conspicuously with a lower Nd content presumably as a result of an increase in the grain size.抄録全体を表示PDF形式でダウンロード (1959K) -
北地 誠, 小林 秀彦, 柿崎 浩一, 平塚 信之2002 年 49 巻 2 号 p. 146-150
発行日: 2002/02/15
公開日: 2009/12/04
ジャーナル フリーThe synthesis of Fe2N powder from FeC2O4 powder and their thermal decomposition behavior were studied, and their magnetic properties were investigated. FeC2O4 powder, which is a starting material of iron nitride, was prepared by the precipitation method in ethanol solvent (FeCl2aq.-H2C2O4⋅EtOH), consequently fine powder was obtained. Fe2N powder was prepared by the thermal decomposition of fine FeC2O4 powder under NH3 gas flow at 410°C, and the pyrolysis temperature was lower than that of FeC2O4 made from water solvent (FeCl2aq.-(NH4)2C2O4aq.). When the Fe2N powder was heated in air and under Ar gas flow, the pyrolysis started at 150°C and 350°C, respectively. Fe3N single phase was obtained by pyrolysis of Fe2N powder at 400°C under Ar gas flow, and iron nitride transformation from paramagnetism to ferromagnetism was caused.抄録全体を表示PDF形式でダウンロード (3817K) -
山元 洋, 塚田 祐二郎2002 年 49 巻 2 号 p. 151-156
発行日: 2002/02/15
公開日: 2009/12/04
ジャーナル フリーExperiments were carried out to investigate the magnetic properties of Sm-Fe-Co-W system nitriding compounds with TbCu7-type structure. Smy(Fe0.95Co0.05)100-x-yWx(x=0-1.0, y=8-11) alloy ribbons were prepared by the single roller rapid-quenching method, and the effects of alloy composition, and conditions of heat-treatment and nitrogenation, were examined with regards to their magnetic properties. The optimum preparation conditions of the compounds are as follows. Composition: {Sm10(Fe0.95Co0.05)89.7W0.3}85.0N15.0, roller velocity: 50 m/s, heat treatment: 675°C×60 min in high-purity Ar gas, and nitriding condition: 400°C×15 h in high-purity N2 gas. Typical magnetic properties of the obtained compound powders are HcJ=765.7 kA/m (9.62 kOe), Jr=0.93 T (96.40 emu/g), (BH)max=134.5 kJ/m3 (16.9 MGOe), and Tc=480°C. It was found that this sample was an exchange spring magnet from TEM photographs and recoil loops of the hysteresis curve. The value of (BH)max for the compression-molded isotropic bonded magnet prepared from the: {Sm10(Fe0.95Co0.05)89.7W0.3}85.0N15.0 powder is 95.0 kJ/m3 (12.0 MGOe), when the density of bonded magnet is 6.1 Mg/m3. And the reversible temperature coefficient of Jr is α(Jr)=-0.071 %/°C, the temperature coefficient of HcJ in the range from 25°C to 125°C obtained by a linear extrapolation is α(HcJ)=-0.42%/°C.抄録全体を表示PDF形式でダウンロード (1967K)
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