scholarly journals Substrate-dependent differences in ferroelectric behavior and phase diagram of Si-doped hafnium oxide

2021 ◽  
Author(s):  
Maximilian Lederer ◽  
Konstantin Mertens ◽  
Ricardo Olivo ◽  
Kati Kühnel ◽  
David Lehninger ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Hafnium Oxide ◽  
Annealing Temperature ◽  
Interface Layer ◽  
Process Window ◽  
Neuromorphic Circuits ◽  
Material Development ◽  
Ferroelectric Behavior ◽  
High Annealing ◽  
Interface Layers

Abstract Non-volatile memories based on ferroelectric hafnium oxide, especially the ferroelectric field-effect transistor (FeFET), have outstanding properties, e.g. for the application in neuromorphic circuits. However, material development has focused so far mainly on metal–ferroelectric–metal (MFM) capacitors, while FeFETs are based on metal–ferroelectric–insulator–semiconductor (MFIS) capacitors. Here, the influence of the interface properties, annealing temperature and Si-doping content are investigated. Antiferroelectric-like behavior is strongly suppressed with a thicker interface layer and high annealing temperature. In addition, high-k interface dielectrics allow for thicker interface layers without retention penalty. Moreover, the process window for ferroelectric behavior is much larger in MFIS capacitors compared to MFM-based films. This does not only highlight the substrate dependence of ferroelectric hafnium oxide films, but also gives evidence that the phase diagram of ferroelectric hafnium oxide is defined by the mechanical stress. Graphic Abstract

Characterization of Mg-Al Sheet Clad Materials Fabricated by Hot Rolling

2007 ◽  
Vol 26-28 ◽  
pp. 409-412 ◽  
Author(s):  
Jae Seol Lee ◽  
Hyeon Taek Son ◽  
Ki Yong Lee ◽  
Soon Sub Park ◽  
Dae Guen Kim ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Vickers Hardness ◽  
Hot Rolling ◽  
High Strength ◽  
Interface Layer ◽  
Rolling Temperature ◽  
Al Alloy ◽  
Clad Sheet ◽  
The Difference ◽  
Interface Layers

AZ31 Mg / 5083 Al clad sheet was fabricated by the hot rolling method and its mechanical properties were investigated in this study. The tensile strength and yield strength of Mg- Al clad samples were slightly higher than that of AZ31 Mg sample, resulting in high strength 5083 Al alloy. Also, in the case of the AZ31 Mg sample, tensile strength indicated different values to the rolling directions. The thickness of interface layers between magnesium and aluminum materials increased with increasing rolling temperature. The thickness of interface layer was about 1.2 μm and 1.6 μm, respectively. The difference of thickness on the interface layer with variation of rolling temperature was attributed to promote the diffusion between magnesium and aluminum materials. The Vickers hardness of Mg-Al interface layer was around 125 Hv. The interface layer composed of hard inter-metallic phases which may act a increment of Vickers hardness depending upon its thickness.

scholarly journals О возможности введения примеси железа в узлы A в SrTiO-=SUB=-3-=/SUB=-

2022 ◽  
Vol 64 (3) ◽  
pp. 345
Author(s):  
И.А. Случинская ◽  
А.И. Лебедев
Keyword(s):  
Annealing Temperature ◽  
Local Environment ◽  
First Principles Calculations ◽  
X Ray Diffraction ◽  
Xafs Spectroscopy ◽  
Deviation From Stoichiometry ◽  
High Annealing ◽  
A Site ◽  
Fe Impurity ◽  
Exafs Spectra

The local environment and oxidation state of the Fe impurity in strontium titanate are studied using XAFS spectroscopy. The influence of annealing temperature and deviation from stoichiometry on the possibility of incorporation of the impurity into the A and B sites of the perovskite structure is studied. The results obtained from the X-ray diffraction, XANES spectra, and EXAFS spectra suggest that at high annealing temperature the iron atoms, at least partially (up to 30%), enter the A sites in SrTiO3. The obtained results agree with results of first-principles calculations, according to which the iron at the A site exhibits strong off-centering (the displacement of ~1 Angstrom), similar to that previously established in SrTiO3 samples doped with Mn and Co.

Static Recrystallization in Aluminum/Graphene Composites

2021 ◽  
Vol 1016 ◽  
pp. 1636-1641
Author(s):  
Xiao Dong Wu ◽  
Xiao Li Liu ◽  
Ling Fei Cao ◽  
Guang Jie Huang
Keyword(s):  
Annealing Temperature ◽  
Static Recrystallization ◽  
Recrystallization Behavior ◽  
High Annealing Temperature ◽  
Graphene Composite ◽  
Pinning Effect ◽  
High Annealing ◽  
Rolled Aluminum ◽  
Strong Pinning ◽  
Cold Rolled

The aim of this work was to analyze the recrystallization behavior of cold rolled Aluminum/graphene composites during annealing. The Aluminum/graphene composite was cold rolled firstly, and then annealed at different temperature (250°C, 300°C, 350°C, 400°C) and for various time (1 h, 2 h, 8 h, 32 h). Full recrystallization did not occur until the annealing temperature was above 300 °C. With annealing temperature increasing from 250 to 300°C, the hardness of the composites decreased from 49.6 to 27.6 HV. Grain growth were not observed at high annealing temperature and longer annealing time, which suggested that Graphene has strong pinning effect on the grain boundary of Aluminum.

Development of AIIBVI Semiconductors Doped with Cr for IRLaser Application

2001 ◽  
Vol 692 ◽  
Author(s):  
V. A. Kasiyan ◽  
R. Z. Shneck ◽  
Z. M. Dashevsky ◽  
S. R. Rotman
Keyword(s):  
Annealing Temperature ◽  
Optical Measurements ◽  
High Electron ◽  
Native Defect ◽  
High Annealing Temperature ◽  
High Electron Mobility ◽  
Gas Source ◽  
Low Temperature Annealing ◽  
High Annealing ◽  
Absorption Measurements

AbstractElectrical and optical measurements obtained with CdSe single crystals doped with chromium from a gas source CrSe over a wide temperature range (500–1050 °C) are compared with ZnSe annealed in liquid metal (Zn). These processes are intended to control the concentrations of the impurity and intrinsic defects. The low temperature annealing of CdSe crystals in CrSe atmosphere allows obtaining high electron mobility up to 9000 cm2/Vs at 80 K and demonstrates the low native defect concentration. A high temperature annealing gives rise to increased electron concentration with decreased mobility. Optical absorption measurements show that at the high annealing temperature effective doping with Cr takes place. The impurity absorption beyond the absorption edge is interpreted by the excitation of Cr++ and Cr+ deep levels

scholarly journals Effect of Annealing on the Interface and Mechanical Properties of Cu-Al-Cu Laminated Composite Prepared with Cold Rolling

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 369
Author(s):  
Xing Fu ◽  
Rui Wang ◽  
Qingfeng Zhu ◽  
Ping Wang ◽  
Yubo Zuo
Keyword(s):  
Mechanical Properties ◽  
Annealing Temperature ◽  
Laminated Composite ◽  
Phase Evolution ◽  
Annealing Process ◽  
High Annealing Temperature ◽  
Roll Bonding ◽  
Cold Roll ◽  
High Annealing ◽  
Cold Roll Bonding

Cu-Al-Cu laminated composite was prepared with cold roll bonding process and annealing was carried out to study the phase evolution during the annealing process and its effect on the mechanical properties of the composite. The experimental results showed that after annealing the brittle intermetallics in the interface mainly includes Al4Cu9, AlCu and Al2Cu. With the increase of annealing temperature, the tensile strength of the composite decreases and the elongation shows a different variation which increases at the beginning and then decreases after a critical point. This phenomenon is related to the evolution of intermetallic compounds in the interface of the composite. It was also found that the crack source of the tensile sample is in the interface and delamination appeared at high annealing temperature (450 °C).

Influences of Plasma Processed Interface Layers on Germanium MOS Devices with ALD Grown HfO2

2007 ◽  
Vol 996 ◽  
Author(s):  
Takuya Sugawara ◽  
Raghavasimhan Sreenivasan ◽  
Yasuhiro Oshima ◽  
Paul C. McIntyre
Keyword(s):  
Electrical Properties ◽  
Interface Layer ◽  
Hafnium Dioxide ◽  
Passivation Layer ◽  
Oxide Semiconductor ◽  
Flat Band ◽  
Mos Capacitors ◽  
Mos Devices ◽  
Interface Layers ◽  
Silicon Based

AbstractGermanium and hafnium-dioxide (HfO2) stack structures' physical and electrical properties were studied based on the comparison of germanium and silicon based metal-oxide-semiconductor (MOS) capacitors' electrical properties. In germanium MOS capacitor with oxide/oxynitride interface layer, larger negative flat-band-voltage (Vfb) shift compared with silicon based MOS capacitors was observed. Secondary ion mass spectrum (SIMS) characteristics of HfO2-germanium stack structure with germanium oxynitride (GeON) interfacial layer showed germanium out diffusion into HfO2. These results indicate that the germanium out diffusion into HfO2 would be the origin of the germanium originated negative Vfb shift. Using Ta3N5 layer as a germanium passivation layer, reduced Vfb shift and negligible hysteresis were observed. These results suggest that the selection of passivation layer strongly influences the electrical properties of germanium based MOS devices.

EFFECT OF UNDERLAYERS ON THE STRESS OF CU FILMS PREPARED USING IONIZED METAL PLASMA

2002 ◽  
Vol 16 (01n02) ◽  
pp. 189-196 ◽  
Author(s):  
C. Y. LI ◽  
D. H. ZHANG ◽  
J. J. WU ◽  
D. X. QI ◽  
Y. QIAN ◽  
...  
Keyword(s):  
Barrier Layer ◽  
Tensile Strain ◽  
Annealing Temperature ◽  
Abrupt Change ◽  
Lattice Mismatch ◽  
Cu Films ◽  
Annealing Temperatures ◽  
Metal Plasma ◽  
High Annealing ◽  
Cu Film

We investigated the effect of barrier metals, Ta, TaN and multi-stacked Ta/TaN , on the stress of the late deposited Cu film using ionised-metal plasma (IMP) technique. It was found that the stress of the IMP Cu film is sensitive to the strain or lattice mismatch of the barrier layer underneath. The nitrogen composition incorporated into Ta barrier layer causes tensile strain in the barrier and also the stress in the late deposited Cu film. The Cu film deposited on a multi-stacked Ta/TaN barrier showed the smallest stress due to relaxation of strain in the multi-layer barrier. In addition, the stress was also found sensitive to the annealing temperature. The abrupt change in the stress at high annealing temperatures coincides well with the formation of Cu 3 Si compound.

Effect of Annealing Temperature on Mechanical Properties of Cold Drawn Pearlitic Steel Wires

2006 ◽  
Vol 118 ◽  
pp. 31-34 ◽  
Author(s):  
Won Jong Nam ◽  
Hyung Rak Song ◽  
Kyung Tae Park
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Pearlitic Steel ◽  
High Annealing Temperature ◽  
Annealing Temperatures ◽  
Steel Wires ◽  
High Annealing

The effects of annealing temperature and annealing time on mechanical properties of cold drawn pearlitic steel wires containing 0.84wt% of silicon were investigated. Annealing treatment was performed on cold drawn steel wires for the temperature range of 200°C to 450°C with the different annealing time of 30sec, 1min, 15min and 1hr. The increase of tensile strength at the low annealing temperatures would be related with strain ageing behavior, while the decrease of tensile strength at the high annealing temperature is due to the spheroidization of cementite plates and the occurrence of recovery of the lamellar ferrite in the pearlite.

scholarly journals Morphology and Phase Transformation of Copper/Aluminium Oxide Films

2018 ◽  
Vol 63 (5) ◽  
pp. 425 ◽  
Author(s):  
A. Panthawan ◽  
T. Kumpika ◽  
W. Sroila ◽  
E. Kantarak ◽  
W. Thongpan ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Atmospheric Pressure ◽  
Annealing Temperature ◽  
Aluminium Oxide ◽  
Single Step ◽  
Band Gaps ◽  
Oxygen Deficit ◽  
Annealing Temperatures ◽  
High Annealing ◽  
Deposited Films

Сopper aluminium oxide (CuAlO2) was successfully prepared within the single-step sparking process at the atmospheric pressure. The as-deposited films were then annealed at 400, 900, 1000, and 1100 ∘C in an oven. The results have shown that the annealing temperature has direct effect on the morphology, phase transformation, and optical properties. CuAlO2 in the delafossite phase was formed on the annealed films at temperatures higher than 900 ∘C. Furthermore, the energy band gaps of the annealed films were linearly increased from 3.3 to 3.8 eV with increasing the annealing temperature from 400 to 1100 ∘C due to a reduction of the oxygen deficit of films at high annealing temperatures.

Sign in / Sign up

Export Citation Format

Share Document