著者

Takenaka Tadashi Nagata Hajime Hiruma Yuji

出版者

Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physics

雑誌

Jpn J Appl Phys (ISSN:00214922)

巻号頁・発行日

vol.47, no.5, pp.3787-3801, 2008-05-25

被引用文献数

4 379

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The dielectric, ferroelectric and piezoelectric properties of perovskite ferroelectric and bismuth layered-structured ferroelectric (BLSF) ceramics are described being superior candidates for lead-free piezoelectric materials to reduce environmental damage. Perovskite-type ceramics seem to be suitable for actuator and high-power applications that require a large piezoelectric constant, $d_{33}$, and a high Curie temperature, $T_{\text{c}}$, or a depolarization temperature, $T_{\text{d}}$ (${>}200$ °C). For BaTiO3-based solid solutions, ($1-x$)BaTiO3–$x$(Bi0.5K0.5)TiO3 (BT–BKT100$x$) ceramics, $T_{\text{c}}$ increases with increasing amount of $x$. The BT–BKT20 + MnCO3 (0.1 wt %) ceramic shows a high $T_{\text{c}}$ greater than 200 °C and an electromechanical coupling factor of $k_{33} =0.35$. In the case of $a$(Bi1/2Na1/2)TiO3–$b$(Bi1/2K1/2)TiO3–$c$BaTiO3 [BNBK (100$a$/100$b$/100$c$)] solid solution ceramics, $d_{33}$ is 191 pC/N for BNBK (85.2/2.8/12). KNbO3 (KN)-based ceramics are also a candidate for lead-free piezoelectrics. In Mn-doped KN ceramics, a higher $k_{33}$ of 0.507 is obtained for KN + MnCO3 (0.1 wt %). On the other hand, BLSF ceramics seem to be excellent candidates as piezoelectric sensors for high temperatures and ceramic resonators with a high mechanical quality factor, $Q_{\text{m}}$, and a low temperature coefficient of resonance frequency, TC-f. The $k_{33}$ value of the donor (Nb)-doped and grain-oriented (HF) Bi4Ti3-xNbxO12 (BITN-$x$) ceramic is 0.39 for $x=0.08$ and is able to keep the same stable value up to 350 °C. Nd(0.01) and V(0.75) co-doped Bi4Ti3O12 ceramics, BNTV$(0.01, 0.75)$, show a relatively low TC-f. Bi3TiTaO9 (BTT)-based solid solution, Srx-1Bi4-xTi2-xTaxO9 [SBTT2($x$)] ($1\leqq x\leqq 2$), displays the high $Q_{\text{m}}$ value ($=13500$) in (p)-mode at $x=1.25$. For resonator applications, (Sr1-xCax)2Bi4Ti5O18 (SCBT) ($0\leqq x\leqq 0.5$) ceramics are suitable.

著者

Ko Tsung-Shine Chen Zheng-Wen Lin Der-Yuh Suh Joonki Chen Zheng-Sheng

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.56, no.4, 2017-03-24

被引用文献数

4

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In this study, Ni-doped MoS<inf>2</inf>was grown by chemical vapor transportation. Photoconductivity results reveal that Ni-doped MoS<inf>2</inf>has an obvious doping level of 1.2 eV and an electrical conductivity of σ ≅ 9.92 × 10⁻⁷S cm⁻¹at room temperature, which is lower than that of undoped MoS<inf>2</inf>(σ ≅ 7.913 × 10⁻⁵S cm⁻¹) owing to the impurity state caused by Ni atoms. Hall effect measurement results indicate that Ni-doped MoS<inf>2</inf>sample is of the n-type and has a higher resistance and a lower mobility than undoped MoS<inf>2</inf>. We further fabricated undoped and Ni-doped MoS<inf>2</inf>photodetectors to understand the operation characteristics of MoS<inf>2</inf>-based photodetectors. Persistent photoconductivity shows that both rise and fall times decreased from 0.33/0.68 to 0.14/0.43 s as Ni atoms were doped in MoS<inf>2</inf>PDs. This work shows that Ni atoms could cause small lattice imperfections to form trap states leading to high resistance, low mobility, small activation energy and short decay time. Therefore, doping Ni atoms in MoS<inf>2</inf>is beneficial for the application of photodetectors.

著者

Mukai Kohki Watanabe Keita Kimura Yuuta

出版者

Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physics

雑誌

Jpn J Appl Phys (ISSN:00214922)

巻号頁・発行日

vol.49, no.4, pp.04DH07-04DH07-4, 2010-04-25

被引用文献数

3

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The lattice constant distribution inside a columnar InAs/GaAs quantum dot (QD) and its crystal orientation dependence were evaluated by grazing incidence X-ray diffraction (GIXD) measurement. The QDs were grown by stacking Stranski-krastanow (SK)-type InAs QDs directly in the growth direction with very thin GaAs interval layers. We evaluated the dependence of the in-plane lattice constant on QD height by GIXD measurement using equipment available for laboratories. We found that the lattice constants at the top and bottom of the QDs were almost the same when the height and diameter of the QDs were almost equal. As the number of stacks was increased to grow high QDs, the lattice constant at the QD top became larger in the [1-10] direction than in the [110] direction, but this relationship was reversed at the bottom. We consider that GIXD measurement with compact equipment will contribute to the swift and efficient development of QD devices.

著者

Kajihara Tadao Ueno Yoshikazu Tsujiura Yuichi Koshiba Yasuko Morimoto Masahiro Kanno Isaku Ishida Kenji

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.56, no.4, 2017-02-03

被引用文献数

8

---

We investigated piezoelectric vibration energy harvesters with poly(vinylidene fluoride/trifluoroethylene) films and the improved power generation from using multistacked and stretched ferroelectric films on the cantilevers. The energy harvesters generated electric power with a resonant frequency of approximately 25 Hz, which corresponded to the ambient vibration. The power density of four-layered harvesters was estimated to be 2.5 µW/m³, which was larger than the power density of previous harvesters. The output power of stretched-film harvesters was 3.6 times the output obtained from unstretched films. In addition, because organic ferroelectric films are flexible, the resonant frequency of each harvester was practically constant even when using the techniques of multistacking and stretching.

著者

Davis Harold A. Keinigs Rhon K. Anderson Wallace E. Atchison Walter L. Bartsch R. Richard Benage John F. Ballard Evan O. Bowman David W. Cochrane James C. Ekdahl Carl A. Elizondo Juan M. Faehl Rickey J. Fulton Robert D. Gribble Robert F. Guzik Joyce A. Kyrala George A. Miller R. Bruce Nielsen Kurt E. Parker Jerald V. Parsons W. Mark Munson Carter P. Oro David M. Rodriguez George E. Rogers Harold H. Scudder David W. Shlachter Jack S. Stokes John L. Taylor Antoinette J. Trainor R. James Turchi Peter J. Wood Blake P.

出版者

公益社団法人 応用物理学会

雑誌

Japanese journal of applied physics. Pt. 1, Regular papers & short notes (ISSN:00214922)

巻号頁・発行日

vol.40, no.2, pp.930-934, 2001-02-28

被引用文献数

8

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Atlas is a pulsed-power facility under development at Los Alamos National Laboratory to drive high-energy density experiments. Atlas will be operational in the summer of 2000 and is optimized for the study of dynamic material properties, hydrodynamics, and dense plasmas under extreme conditions. Atlas is designed to implode heavy-liner loads in a z-pinch configuration. The peak current of 30 MA is delivered in 4 $\mu$s. A typical Atlas liner is a 47-gram-aluminum cylinder with ${\sim}4$-cm radius and 4-cm length. Three to five MJ of kinetic energy will be delivered to the load. Using composite layers and a variety of interior target designs, a wide variety of experiments in ${\sim}\text{cm}^{3}$ volumes will be performed. Atlas applications, machine design, and the status of the project are reviewed.

著者

Sako Teiyu Kimura Yasuyuki Hayakawa Reinosuke Okabe Nobuhiro Suzuki Yoshiichi

出版者

公益社団法人 応用物理学会

雑誌

Japanese Journal of Applied Physics (ISSN:00214922)

巻号頁・発行日

vol.35, no.2, pp.679-682, 1996

被引用文献数

4

---

The Smectic-A (SmA) phases of the antiferroelectric liquid crystals (R)-MHPOBC, (R)-MHPOCBC and slightly racemized MHPOBC (R:S=17:3) have been studied by means of simultaneous measurements of the electric displacement and the tilt angle induced by the electric field. The SmA-SmC<SUB>α</SUB><SUP>*</SUP> phase transition was observed in (R)-MHPOBC and (R)-MHPOCBC, while a phase transition similar to the SmA-SmC<SUP>*</SUP> one was observed in slightly racemized MHPOBC. In both cases, the Landau-type phenomenological theory explains well the critical behavior in the SmA phase, and the coefficients related to the theory can be determined.

著者

Sako Teiyu Kimura Yasuyuki Hayakawa Reinosuke Okabe Nobuhiro Suzuki Yoshiichi

出版者

INSTITUTE OF PURE AND APPLIED PHYSICS

雑誌

Jpn J Appl Phys (ISSN:00214922)

巻号頁・発行日

vol.35, no.2, pp.679-682, 1996-02-15

被引用文献数

4

---

The Smectic-A (SmA) phases of the antiferroelectric liquid crystals (R)-MHPOBC, (R)-MHPOCBC and slightly racemized MHPOBC (R:S=17:3) have been studied by means of simultaneous measurements of the electric displacement and the tilt angle induced by the electric field. The SmA–SmCα* phase transition was observed in (R)-MHPOBC and (R)-MHPOCBC, while a phase transition similar to the SmA–SmC* one was observed in slightly racemized MHPOBC. In both cases, the Landau-type phenomenological theory explains well the critical behavior in the SmA phase, and the coefficients related to the theory can be determined.

著者

Zheng Hong Reaney Ian M. Muir Duncan Price Tim Iddles David M.

出版者

Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physics

雑誌

Japanese journal of applied physics. Pt. 1, Regular papers & short notes (ISSN:00214922)

巻号頁・発行日

vol.44, no.5, pp.3087-3090, 2005-05-15

被引用文献数

14

---

BaLa4Ti4O15 (BLT) is a hexagonal perovskite-related compound with a temperature coefficient of resonant frequency ($\tau_{\text{f}}$) of $-2$ ppm/°C, relative permittivity $(\varepsilon_{\text{r}})\sim 44$ and figure of merit $(Q\cdot f)\sim 44000$ GHz. Ba4Nd9.333Ti18O54 (BNT) has a tungsten-bronze-related structure with $\varepsilon_{\text{r}}\sim 78$, $Q\cdot f\approx 11000$ GHz and $\tau_{\text{f}}$ of $+47$ ppm/°C. The microstructures and microwave dielectric properties of $x$BNT–($1-x$)BLT ($0\leq x\leq 1$) composite ceramics have been studied. X-ray diffraction analysis and scanning electron microscopy revealed that there was limited inter-reaction between the two phases and that samples were composed largely of BNT and BLT, although some deterioration in measured $\varepsilon_{\text{r}}$ with respect to calculated values was observed. The optimum compositions were $x=0.55$ and 0.75 for which $\varepsilon_{\text{r}}\sim 63$, $\tau_{\text{f}}\sim-20$ ppm/°C and $Q\cdot f>10{,}000$ GHz.

著者

Kojima Yuta Hirose Tetsuya Tsubaki Keishi Ozaki Toshihiro Asano Hiroki Kuroki Nobutaka Numa Masahiro

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.55, no.4, 2016-03-16

被引用文献数

9

---

In this paper, we present a fully on-chip switched-capacitor DC–DC converter for low-voltage CMOS LSIs. The converter has three terminals of input, ground, and output, by developing control circuits with fully on-chip configuration. We employ an ultra low-power nanoampere bias current and voltage reference circuit to achieve ultra low-power dissipation of control circuits. It enables us to realize a highly efficient power conversion circuit at light-load-current applications. The converter achieves highly efficient and robust voltage conversion using a pulse frequency modulation control circuit and a start-up/fail-safe circuit. Measurement results demonstrated that the converter can convert a 3.0 V input into 1.2 V output successfully. The start-up and fail-safe operations were confirmed through the measurement. The efficiency was more than 50% in the range of 2–6 µA load current.

著者

Kimura Yoshinari Kitamura Masatoshi Kitani Asahi Arakawa Yasuhiko

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.55, no.2, 2016-01-22

被引用文献数

3

---

Pentacene-based organic thin-film transistors (TFTs) having a SiO<inf>2</inf>gate dielectric treated with oxygen plasma have been investigated for control of the threshold voltage. The threshold voltage changed in the wide range from −15 to 80 V, depending on plasma treatment time, AC power for plasma generation, and gate dielectric thickness. The threshold voltage change was attributed to negative charges induced on and/or near the surface of the gate dielectric. The threshold voltage change on the order of 1 V was particularly proportional to plasma treatment time. The predictable change enables the control of threshold voltage in this range. In addition, the effect of gate bias stress on threshold voltage was examined. The results suggested that gate bias stress does not negate the threshold voltage change induced by plasma treatment.

著者

Tatara Shingo Kuzumoto Yasutaka Kitamura Masatoshi

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.55, no.3, 2016-01-15

被引用文献数

19

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The surface properties, including work function and wettability, of Au and Ag surfaces modified with various substituted benzenethiols have been investigated. Whereas the work functions of the modified Au surfaces ranged from 4.42 to 5.48 eV, those of the modified Ag surfaces ranged from 3.99 to 5.77 eV. The highest work function of 5.77 eV was obtained on the Ag surface modified with pentafluorobenzenethiol, and the lowest work function of 3.99 eV was obtained on the Ag surface modified with 4-methylbenzenethiol. The water contact angle on modified Au surfaces was found to be in a wide range from 30.9 to 88.3°. The water contact angle on the Au surface modified with a substituted benzenethiol was close to that on the Ag surface modified with the same benzenethiol. Furthermore, the tension of the modified Au surfaces was estimated from their contact angles of water and ethylene glycol.

著者

Kitani Asahi Kimura Yoshinari Kitamura Masatoshi Arakawa Yasuhiko

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.55, no.3, 2016-01-07

被引用文献数

9

---

The threshold voltage in p-channel organic thin-film transistors (TFTs) having dinaphthothienothiophene as a channel material has been investigated toward their applicability to logic circuits. Oxygen plasma treatment of the gate dielectric surface was carried out to control the threshold voltage. The threshold voltage changed in the range from −6.4 to 9.4 V, depending on plasma treatment time and the thickness of the gate dielectric. The surface charge after plasma treatment was estimated from the dependence of the threshold voltage. Operation of logic inverters consisting of TFTs with different threshold voltages was demonstrated as an application of TFTs with controlled threshold voltage.

著者

Horike Shohei Misaki Masahiro Koshiba Yasuko Saito Takeshi Ishida Kenji

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.55, no.3, 2015-12-18

被引用文献数

10

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We have investigated the thermoelectric power of single-wall carbon nanotubes (SWCNTs) with an ionic liquid (IL). The SWCNT/IL films showed simultaneous increase in electrical conductivity and the Seebeck coefficient compared with the pristine SWCNT. No thermoelectric power was observed for the IL. The X-ray diffraction pattern and impedance diagram showed a unique behavior with the concentration of IL, which implies that the interaction between the SWCNTs and IL enhances the thermoelectric power of the SWCNTs. As a result of the simultaneous increase in these parameters, the power factor exhibited a 10-fold increase.

著者

Sugano Koji Suekuni Keisuke Takeshita Toshimitsu Aiba Kiyohito Isono Yoshitada

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.54, no.6, 2015-05-28

被引用文献数

11

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A micro/nanofluidic device containing linearly arranged gold nanoparticles embedded in nanochannels was developed for highly sensitive and highly efficient surface-enhanced Raman spectroscopy (SERS). The Si nanochannel array was fabricated using a photolithography-based process. The nanochannel width was controlled from 100 to 400 nm. Synthesized particles of mean diameter 100 nm were arranged linearly in the nanochannels, using a nanotrench-guided self-assembly process. We developed a process for integrating linearly arranged nanoparticles and micro/nanofluidic components. The particle geometry provided significant Raman enhancement. Furthermore, efficient Raman analysis was possible by scanning a laser spot, because the particles were arranged in one direction. The fabricated structures were evaluated for SERS using 4,4′-bipyridine molecules at concentrations of 1 mM and 10 µM. The Raman peaks was obtained from a few hot spots. The Raman spectra showed that the molecule-specific Raman intensities were correlated with the number of hot spots in the nanochannel.

著者

Morimoto Masahiro Koshiba Yasuko Misaki Masahiro Ishida Kenji

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.54, no.4, 2015-03-27

被引用文献数

8

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We have investigated the pyro- and piezoelectric properties of polyurea spin-coated films with thermal and chemical stability and their performance as infrared sensors. The piezoelectric coefficient d<inf>33</inf>was measured by a laser Doppler vibrometer to be 23.5 pC/N. This coefficient increased with the poling electric field up to around 75 MV/m, suggesting that the polyurea dipole is aligned by applying an electric field greater than 75 MV/m. When a triangular thermal wave was applied, a square-wave pyroelectric current was observed and the pyroelectric coefficient measured to be 5.11 µC/(m²·K). The infrared sensor performance of the polyurea thin film was examined by measuring the voltage sensitivity to infrared irradiation. The obtained result of 70.4 V/W at 1 Hz is consistent with the results calculated from the measured pyroelectric coefficient. Our findings suggest that the performance of the sensor may be improved by increasing the pyroelectric coefficient of the polyurea films.

著者

Ozaki Toshihiro Hirose Tetsuya Tsubaki Keishi Kuroki Nobutaka Numa Masahiro

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.54, no.4, 2015-03-27

被引用文献数

3

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In this paper, we present a rail-to-rail folded-cascode amplifier (AMP) with adaptive biasing circuits (ABCs). The circuit uses a nano ampere current reference circuit to achieve ultralow-power and ABCs to achieve high-speed operation. The ABCs are based on conventional circuits and modified to be suitable for rail-to-rail operation. The measurement results demonstrated that the AMP with the proposed ABCs can operate with an ultralow-power of 384 nA when the input voltage was 0.9 V and achieve high speeds of 0.162 V/µs at the rise time and 0.233 V/µs at the fall time when the input pulse frequency and the amplitude were 10 kHz and 1.5 V<inf>pp</inf>, respectively.

著者

OHMI Tadahiro

出版者

社団法人応用物理学会

雑誌

Japanese journal of applied physics. Pt. 1, Regular papers & short notes (ISSN:00214922)

巻号頁・発行日

vol.33, no.12, pp.6747-6755, 1994-12-30

被引用文献数

11 21

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In addition to three-terminal devices such as metal oxide semiconductor (MOS) transistors and bipolar transistors, the introduction of four-terminal devices such as neuron MOS transistor is essentially required for the realization of intelligent ULSI systems which is most crucial for electronics in the 21st century. Four-terminal devices will allow us to make ULSI hardware more flexible, real-time programmable, and thus more intelligent based on bi-nary multi-valued analog-merged hardware computation algorithm. For such systems to work, we must establish high-accuracy device fabrication processes based on the concept of ultraclean technology. The simultaneous fulfillment of three principles, viz. ultraclean wafer surface, ultraclean processing environment, and perfect process-parameter control, is the key to high-performance processes for fabricating advanced subhalf-micron and sub-quarter-micron ULSI devices. Advanced process technologies have been realized for the first time by ultraclean processing, making it possible to establish total low-temperature processing, such as gate oxidation at 45O℃, implanted region anneal at 45O℃, BPSG film reflow at 45O℃ and single-crystal silicon epitaxy with simultaneous doping at 3OO℃ by introducing very well regulated ion bombardment during processing which is most essential for obtaining high-performance subhalf-micron and subquarter-micron ULSI.

著者

Hoshi Takayuki Ochiai Yoichi Rekimoto Jun

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.53, no.7, 2014-06-12

被引用文献数

70

著者

Yon Guk-Hyon Buh Gyoung Ho Park Tai-su Hong Soo-Jin Shin Yu Gyun Chung U-In Moon Joo-Tae

出版者

Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physics

雑誌

Jpn J Appl Phys (ISSN:00214922)

巻号頁・発行日

vol.45, no.4, pp.2961-2964, 2006-04-30

被引用文献数

2 9

---

Plasma doping and laser annealing are successfully integrated into the conventional p-metal–oxide–silicon field effect transistor (PMOSFET) process to form ultra shallow junction (USJ). Comparing with the conventional combination of ion implantations and rapid thermal annealing (RTA), junction depth ($X_{\text{J}}$) and sheet resistance ($R_{\text{S}}$) are reduced. Also, significant improvement of the short channel effects without the degradation of on-current is observed.

著者

Usui Akira Sunakawa Haruo Sakai Akira YAMAGUCHI A. Atsushi

出版者

社団法人応用物理学会

雑誌

Japanese journal of applied physics. Pt. 2, Letters (ISSN:00214922)

巻号頁・発行日

vol.36, no.7, pp.L899-L902, 1997-07-15

被引用文献数

113 792

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Thick GaN layers were grown by hydride vapor phase epitaxy (HVPE) with the aim of using these layers as a homoepitaxial substrate to improve device quality of laser diodes or light emitting diodes. HVPE is very useful for thick layer growth since the growth rate can reach from several ten up to one hundred micron per hour. In this experiment, the growth began as selective growth through openings formed in a SiO_2 mask. Facets consisting of {1101} planes were formed in the early stage and a continuous film developed from the coalescence of these facets on the SiO_2 mask. As a result, GaN layers with a dislocation density as low as 6 × 10^7 cm^-2 were grown on 2-inch-diameter sapphire wafers. These GaN layers were crack-free and had mirror-like surface.