Seismic properties of lawsonite eclogites from the southern Motagua fault zone, Guatemala

Kim, D.,Wallis, S.,Endo, S.,Ree, J.H. Elsevier Scientific Publishing Co 2016 Tectonophysics Vol.677 No.-

<P>We present new data on the crystal preferred orientation (CPO) and seismic properties of omphacite and lawsonite in extremely fresh eclogite from the southern Motagua fault zone, Guatemala, to discuss the seismic anisotropy of subducting oceanic crust. The CPO of omphacite is characterized by (010)[001], and it shows P-wave seismic anisotropies (AV(P)) of 1.4%-3.2% and S-wave seismic anisotropies (AV(S)) of 1.4%-2.7%. Lawsonite exhibits (001) planes parallel to the foliation and [010] axes parallel to the lineation, and seismic anisotropies of 1.7%-6.6%AV(P) and 3.4%-14.7% AV(S). The seismic anisotropy of a rock mass consisting solely of omphacite and lawsonite is 1.2%-4.1%AV(P) and 1.8%-6.8%AV(S). For events that propagate more or less parallel to the maximum extension direction, X, the fast S-wave velocity (Vs) polarization is parallel to the Z in the Y-Z section (rotated from the X-Z section), causing trench-normal seismic anisotropy for orthogonal subduction. Based on the high modal abundance and strong fabric of lawsonite, the AV(S) of eclogites is estimated as similar to 11.7% in the case that lawsonite makes up similar to 75% of the rock mass. On this basis, we suggest that lawsonite in both blueschist and eclogite may play important roles in the formation of complex pattern of seismic anisotropy observed in NE Japan: weak trench-parallel anisotropy in the forearc basin domains and trench-normal anisotropy in the backarc region. (C) 2016 Elsevier B.V. All rights reserved.</P>

Rigorous Design of 22-㎚ Node 4-Terminal SOI FinFETs for Reliable Low Standby Power Operation with Semi-empirical Parameters

Seongjae Cho,Shinichi O’uchi,Kazuhiko Endo,Sang Wan Kim,Younghwan Son,In Man Kang,Meishoku Masahara,James S. Harris,Byung-Gook Park 대한전자공학회 2010 Journal of semiconductor technology and science Vol.10 No.4

In this work, reliable methodology for device design is presented. Based on this method, the underlap length has been optimized for minimizing the gateinduced drain leakage (GIDL) in a 22-㎚ node 4-terminal (4-T) silicon-on-insulator (SOI) fin-shaped field effect transistor (FinFET) by TCAD simulation. In order to examine the effects of underlap length on GIDL more realistically, doping profile of the source and drain (S/D) junctions, carrier lifetimes, and the parameters for a band-to-band tunneling (BTBT) model have been experimentally extracted from the devices of 90-㎚ channel length as well as pnjunction test element groups (TEGs). It was confirmed that the underlap length should be near 15 ㎚ to suppress GIDL effectively for reliable low standby power (LSTP) operation.

Rigorous Design of 22-nm Node 4-Terminal SOI FinFETs for Reliable Low Standby Power Operation with Semi-empirical Parameters

조성재,Shinichi O’uchi,Kazuhiko Endo,김상완,Younghwan Son,Meishoku Masahara,James S. Harris, Jr.,박병국,강인만 대한전자공학회 2010 Journal of semiconductor technology and science Vol.10 No.4

In this work, reliable methodology for device design is presented. Based on this method, the underlap length has been optimized for minimizing the gateinduced drain leakage (GIDL) in a 22-nm node 4-terminal (4-T) silicon-on-insulator (SOI) fin-shaped field effect transistor (FinFET) by TCAD simulation. In order to examine the effects of underlap length on GIDL more realistically, doping profile of the source and drain (S/D) junctions, carrier lifetimes, and the parameters for a band-to-band tunneling (BTBT)model have been experimentally extracted from the devices of 90-nm channel length as well as pnjunction test element groups (TEGs). It was confirmed that the underlap length should be near 15nm to suppress GIDL effectively for reliable low standby power (LSTP) operation.

Rigorous Design of 22-nm Node 4-Terminal SOI FinFETs for Reliable Low Standby Power Operation with Semi-empirical Parameters

Cho, Seong-Jae,O'uchi, Shinichi,Endo, Kazuhiko,Kim, Sang-Wan,Son, Young-Hwan,Kang, In-Man,Masahara, Meishoku,Harris, James S.Jr,Park, Byung-Gook The Institute of Electronics and Information Engin 2010 Journal of semiconductor technology and science Vol.10 No.4

In this work, reliable methodology for device design is presented. Based on this method, the underlap length has been optimized for minimizing the gateinduced drain leakage (GIDL) in a 22-nm node 4-terminal (4-T) silicon-on-insulator (SOI) fin-shaped field effect transistor (FinFET) by TCAD simulation. In order to examine the effects of underlap length on GIDL more realistically, doping profile of the source and drain (S/D) junctions, carrier lifetimes, and the parameters for a band-to-band tunneling (BTBT) model have been experimentally extracted from the devices of 90-nm channel length as well as pnjunction test element groups (TEGs). It was confirmed that the underlap length should be near 15 nm to suppress GIDL effectively for reliable low standby power (LSTP) operation.

PRESSURE DEPENDENCE OF THE CURIE TEMPERATURE IN MnAlGe

S. Endo,H. Matsuzaki,F. Ono,T. Kanomata,T. Kaneko 한국자기학회 1995 韓國磁氣學會誌 Vol.5 No.5

The pressure dependence of the Curie temperature was determined in 2dimensional like ferromagnet, MnAlGe up to a maximum pressure of 7.5 ㎬ through measurements of electric resistance vs temperature curves. The pressure coefficient was positive with a considerably high rate of 9 K/㎬ in the low pressure ragion, while it decreased gradually down to one order of magnitude smaller value at the maximum pressure. It was concluded that ther is an upper limit of about 550 K in the super-exchange type ferromagnetic interaction between Mn layers.

A novel one-step electrochemical method to obtain crystalline titanium dioxide films at low temperature

S. Karuppuchamy,N. Suzuki,S. Ito,T. Endo 한국물리학회 2009 Current Applied Physics Vol.9 No.1

A crystalline titanium dioxide (TiO2) thin film on various metal substrates such as hot-dip-galvanized (HDG), electrochemically galvanized (EG) and cold rolled steel (CRS) has been successfully prepared for the first time by simple one-step electrodeposition method from alkaline aqueous solution containing potassium titanium oxalate and hydroxylamine. The as-grown titanium dioxide films are composed of a mixture of anatase, rutile and brookite structures and have a good crystalline state. The present investigation reveals that the electrochemical deposition of crystalline titanium dioxide on different metal substrates from single electrochemical bath is possible and very promising as a preparation method for industrial applications. A crystalline titanium dioxide (TiO2) thin film on various metal substrates such as hot-dip-galvanized (HDG), electrochemically galvanized (EG) and cold rolled steel (CRS) has been successfully prepared for the first time by simple one-step electrodeposition method from alkaline aqueous solution containing potassium titanium oxalate and hydroxylamine. The as-grown titanium dioxide films are composed of a mixture of anatase, rutile and brookite structures and have a good crystalline state. The present investigation reveals that the electrochemical deposition of crystalline titanium dioxide on different metal substrates from single electrochemical bath is possible and very promising as a preparation method for industrial applications.

EFFECT OF HARDNESS CHANGES AND MICROSTRUCTURAL DEGRADATION ON CREEP BEHAVIOR OF A Mod.9Cr-1Mo STEEL

K-S. PARK,H-S. CHUNG,K-J. LEE,Y-G. JUNG,C-Y. KANG T. ENDO 한국자동차공학회 2005 International journal of automotive technology Vol.6 No.1

Interrupted creep tests for investigating the structural degradation during creep were conducted for a Mod 9Cr-1Mo steel in the range of stress from 71 to 167 MPa and temperature from 873 to 923 K. The change of hardness and tempered martensitic lath width was measured in grip and gauge parts of interrupted creep specimens. The lath structure was therimally stable in static conditions. However, it was not stable during creep, and the structural change was enhanced by creep strain. The relation between the change in lath width and creep strain was described quantitatively. The change in Vickers hardness was expressed by a single valued function of creep LCR(life consumption ratio). Based on the empirical relation between strain and lath width, a model was proposed to describe the relation between change in hardness and creep LCR. The comparison of the model with the empirical relation suggests that about 65% of hardness loss is due to the decrease of dislocation density accompanied by the movement of lath boundaries. The role of precipitates on subboundaries was discussed in connection with the abnormal subgrain growth appearing in low stress regime.

EFFECT OF HARDNESS CHANGES AND MICROSTRUCTURAL DEGRADATION ON CREEP BEHAVIOR OF A Mod.9Cr-1Mo STEEL

PARK K. S.,CHUNG H. S.,LEE K. J.,JUNG Y. G.,KANG C. Y.,ENDO T. The Korean Society of Automotive Engineers 2005 International journal of automotive technology Vol.6 No.1

Interrupted creep tests for investigating the structural degradation during creep were conducted for a Mod.9Cr-1Mo steel in the range of stress from 71 to 167 MPa and temperature from 873 to 923 K. The change of hardness and tempered martensitic lath width was measured in grip and gauge parts of interrupted creep specimens. The lath structure was thermally stable in static conditions. However, it was not stable during creep, and the structural change was enhanced by creep strain. The relation between the change in lath width and creep strain was described quantitatively. The change in Vickers hardness was expressed by a single valued function of creep LCR(life consumption ratio). Based on the empirical relation between strain and lath width, a model was proposed to describe the relation between change in hardness and creep LCR. The comparison of the model with the empirical relation suggests that about 65% of hardness loss is due to the decrease of dislocation density accompanied by the movement of lath boundaries. The role of precipitates on subboundaries was discussed in connection with the abnormal subgrain growth appearing in low stress regime.

From high pressure radial collapse to graphene ribbon formation in triple-wall carbon nanotubes

Silva-Santos, S.D.,Alencar, R.S.,Aguiar, A.L.,Kim, Y.A.,Muramatsu, H.,Endo, M.,Blanchard, N.P.,San-Miguel, A.,Souza Filho, A.G. Elsevier 2019 Carbon Vol.141 No.-

<P><B>Abstract</B></P> <P>The radial stability and the irreversible transformation of triple-wall carbon nanotubes (TWCNTs) bundles are investigated at high pressure conditions both experimentally and theoretically (exp. up 72 GPa). The tubes having a mean internal diameter of 0.83 nm and graphite-like intertube distance, show an onset of the radial collapse evidenced by the evolution of optical phonons. The nanotube collapse onset is observed at ∼ 22 GPa completes for the two external tubes at ∼ 29 GPa, however the innermost tube remains stable up to ∼ 37 GPa. Molecular dynamic calculations performed on smaller diameter TWCNTs bundles, as a model system, confirmed the multiple-stage pressure-induced collapse process. An analytical expression for the collapse pressure of carbon nanotubes having an arbitrary number of walls is proposed. Our experiments and modelling show that for pressures beyond ∼ 60 GPa an irreversible structural transformation of TWCNTs takes place. <I>Ex situ</I> transmission electron microscopy characterization on the recovered sample from 72 GPa revealed the mechanical failure of carbon nanotubes which evolve towards ribbon-like structures as corroborated by Raman spectroscopy. Modelling the tubes evolution at high pressure and high temperature showed the formation of new structures ranging from ribbon-like to graphite-like with either different degrees of amorphization or s <SUP> p 3 </SUP> interlinking.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Linear carbon chains inside multi-walled carbon nanotubes: Growth mechanism, thermal stability and electrical properties

Kang, C.S.,Fujisawa, K.,Ko, Y.I.,Muramatsu, H.,Hayashi, T.,Endo, M.,Kim, H.J.,Lim, D.,Kim, J.H.,Jung, Y.C.,Terrones, M.,Dresselhaus, M.S.,Kim, Y.A. Pergamon Press ; Elsevier Science Ltd 2016 Carbon Vol.107 No.-

<P>Linear carbon chains (LCCs) consisting of sp-hybridized carbon atoms are considered a fascinating 1D system and could be used in the fabrication of the next-generation molecular devices because of its ideal linear atomic nature. A large portion of long LCCs inside multi-walled carbon nanotubes (MWCNTs) were synthesized by atmospheric arc discharge in the presence of boron. Closed-end growth of MWCNTs in the arc process is suggested as a critical condition for the simultaneous growth of LCCs within the inner cores of carbon nanotubes. The strong Raman line around 1850 cm(-1) was used to characterize the degree of filling as well as their structural stability under high temperature thermal treatments. We observed a distinctive change in the electrical conductivity of the MWCNT assembly before and after the disappearance of LCCs due to the expected strong coupling interaction between the LCCs and the innermost tube. This work demonstrates for the first time the enhanced effect of confined linear carbon chains on the overall electrical conductivity of MWCNT assemblies. (C) 2016 Elsevier Ltd. All rights reserved.</P>