Results 221 to 230 of about 3,150 (261)

Ferroelectricity in undoped hafnium oxide

Applied Physics Letters, 2015
We report the observation of ferroelectric characteristics in undoped hafnium oxide thin films in a thickness range of 4–20 nm. The undoped films were fabricated using atomic layer deposition (ALD) and embedded into titanium nitride based metal-insulator-metal (MIM) capacitors for electrical evaluation. Structural as well as electrical evidence for the
Patrick Polakowski, Johannes Müller
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Plasma electrolytic oxidation of hafnium

International Journal of Refractory Metals and Hard Materials, 2017
Abstract This paper presents the results of the investigation of plasma electrolytic oxidation (PEO) of hafnium. Atoms ionized during the PEO micro-discharging were identified using optical emission spectroscopy. The spectral line shape analysis of the hydrogen Balmer line H β indicated the presence of two types of micro-discharges characterized by ...
Stevan Stojadinović, Nenad Tadić, Rastko Vasilić   +2 more
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Oxidation of hafnium carbide and hafnium carbide with additions of tantalum and praseodymium

Oxidation of Metals, 1991
The oxidation behavior of HfC, HfC-25 wt. % TaC, and HfC-7 wt.% PrC2 has been studied between 1200–2200° C. Parabolic growth of the oxide layer has been observed for both HfC and HfC-TaC over the entire temperature range. A break in the temperature dependence of the oxidation kinetics occurs around 1600°C.
E. L. Courtright, J. T. Prater, G. R. Holcomb, G. R. St. Pierre, R. A. Rapp   +4 more
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Zirconium and Hafnium Twin Monomers for Mixed Oxides

ChemPlusChem, 2014
AbstractThe synthesis of Zr and Hf twin monomers of type [M(2‐OCH2cC4H3O)4(x HOCH2cC4H3O)] (3, M=Zr, x=0; 4, M=Hf, x=1) and M[(2‐OCH2‐C6H4O)2(2‐HOCH2‐C6H4OH)] (5, M=Zr; 6, M=Hf) by reacting M(OR)4 (M=Zr, R=nC3H7, 1; M=Hf, R=nC4H9, 2) with 2‐furylmethanol or 2‐hydroxybenzyl alcohol is discussed. Complexes 3–6 were homopolymerized under acidic conditions.
Christian, Schliebe, Thomas, Gemming, Julian, Noll, Lutz, Mertens, Michael, Mehring, Andreas, Seifert, Stefan, Spange, Heinrich, Lang   +7 more
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Hafnium oxoneopentoxide as a new MOCVD precursor for hafnium oxide films

Journal of Crystal Growth, 2004
Abstract The reaction between hafnium tetrachloride and neopentyl alcohol in the presence of ammonia lead to hafnium oxoneopentoxide ( 1 ). 1 was characterized by FT-IR, 1 H and 13 C NMR. Single-crystal X-ray diffraction identified it as a trinuclear oxo species Hf 3 (μ 3 -O)(μ 3 -ONep)(μ-ONep) 3 (ONep) 6 .
Abrutis, A., Hubert-Pfalzgraf, L.G., Pasko, S., Bartasyte, A., Weiss, F., Janickis, V.   +5 more
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ChemInform Abstract: SELF‐DIFFUSION OF ERBIUM AND HAFNIUM IN POLYCRYSTALLINE ERBIUM OXIDE‐STABILIZED HAFNIUM OXIDE

Chemischer Informationsdienst, 1983
AbstractDie Kationenselbstdiffusionskoeffizienten in Er2O3 ‐stabilisiertem HfO2 werden mit Hilfe einer Tracermethode im Zusammensetzungsbereich 10‐40 mol‐% Er, O3 und bei Temp. zwischen 1700 und 2030°C untersucht.
R. J. TESCH, C. D. WIRKUS, M. F. BERARD
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Hafnium Oxide in Tungsten Filaments

Nature, 1925
IT has been known for a long time that perfectly pure tungsten cannot be used for the manufacture of filaments for electric lamps on account of its “off-setting” structure due to recrystallisation. It has been found also that recrystallisation can be essentially influenced by suitable additions.
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The flexoelectric effect in Al-doped hafnium oxide

Nanoscale, 2018
After the observation of ferroelectric HfO2, interest in ferroelectric-based nanoelectronics has been renewed. However, ferroelectrics also show coupling between the electrical polarization and the deformation gradient, defined as flexoelectricity. Here we show the flexoelectric effect in Al-doped hafnium oxide.
Umberto Celano, Mihaela Popovici, Karine Florent, Simone Lavizzari, Paola Favia, Kris Paulussen, Hugo Bender, Luca di Piazza, Jan Van Houdt, Wilfried Vandervorst   +9 more
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Cytotoxicity and physicochemical properties of hafnium oxide nanoparticles

Chemosphere, 2011
Nano-sized hafnium oxide (HfO(2)) particles are being considered for applications within the semiconductor industry. However, little is known about their cytotoxicity. The objective of this work was to assess several HfO(2) nanoparticles (NPs) samples for their acute cytotoxicity.
James A, Field, Antonia, Luna-Velasco, Scott A, Boitano, Farhang, Shadman, Buddy D, Ratner, Chris, Barnes, Reyes, Sierra-Alvarez   +6 more
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Reduction of Zirconium and Hafnium Oxides

Nature, 1961
MANY attempts have been made to reduce zirconium dioxide with hydrogen. At temperatures up to 1,500°C. no positive results have been reported1–3. Newbury and Pring4 reported that at 2,500°C. and a hydrogen pressure of 150 atm. no reduction took place. Mott5 stated that in an electric arc at 6,000°C. and at a hydrogen pressure of 22 atm.
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