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Hafnium Oxide Pellets | AMERICAN ELEMENTS

Hafnium (atomic symbol: Hf, atomic number: 72) is a Block D, Group 4, Period 6 element with an atomic weight of 178.49. The number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electron configuration is [Xe] 4f 14 5d 2 6s 2.

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Thermoanalytical investigation of crystalline layered hafnium salts

Transition metal containing hafnium phosphates forms has layered monoclinic structure. In general these materials have similar route of thermal decomposition; i.e. they loss their crystal water first then at a higher temperature their structural one. At least the result HfP 2 O 7 goes through phase change at about 1000 K. In detail among their …

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Carbides | AMERICAN ELEMENTS

Carbides are compounds in which the anion is one or more carbon atoms. Most metals form carbide compounds, though not all--indium and gallium, for example, do not. American Elements' manufacturing emphasizes production of metallic carbide materials including boron carbide, cobalt carbide, chromium carbide, hafnium carbide, molybdenum …

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Hafnium Pellets | AMERICAN ELEMENTS

72 Hf 178.480000000 Hafnium. See more Hafnium products. Hafnium (atomic symbol: Hf, atomic number: 72) is a Block D, Group 4, Period 6 element with an atomic weight of 178.49. The number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electron configuration is [Xe] 4f 14 5d 2 6s 2. The hafnium atom has a radius of 159 pm ...

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Direct Ester Condensation from a 1:1 Mixture of

Download Citation | Direct Ester Condensation from a 1:1 Mixture of Carboxylic Acids and Alcohols Catalyzed by Hafnium(IV) or Zirconium(IV) Salts. | To promote atom efficiency in synthesis and to ...

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Direct Condensation of Carboxylic Acids with Alcohols Catalyzed …

Ishihara, Ohara, and Yamamoto (2000) reported that loading of 0.2 mol % of a Hafnium (IV) salt, HfCl 4 · (THF) 2 can efficiently catalyze an equimolar mixture (10 mmol) of carboxylic acid and ...

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Hafnium Sulfate | AMERICAN ELEMENTS

Hafnium Sulfate is a moderately water and acid soluble Hafnium source for uses compatible with sulfates. Sulfate compounds are salts or esters of sulfuric acid formed by replacing …

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The toxicologic and pharmacologic effects of hafnium salts

The toxicologic and pharmacologic effects of hafnium salts. The toxicologic and pharmacologic effects of hafnium salts Toxicol Appl Pharmacol. 1962 Mar;4:238-46. doi: 10.1016/0041-008x(62)90062-5. Authors T J HALEY, K RAYMOND, N KOMESU, H C UPHAM. PMID: 13903825 ...

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Hafnium Acetate | AMERICAN ELEMENTS

About Hafnium Acetate. Hafnium Acetate is a moderately water soluble crystalline Hafnium source that decomposes to Hafnium oxide on heating. It is generally immediately available in most volumes. All metallic acetates are inorganic salts containing a metal …

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Hafnium salts of dodeca-tungstophosphoric acid catalysts for liquid

Among all catalysts 20wt% Nb0.4TPA/TiO2 catalyst showed best catalytic performance towards EMF with a yield of 76% at 130 οC after 6 h. The catalyst is recyclable without any depletion of ...

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Preparation of iridium‑hafnium intermetallic compound coatings in

A uniform and continuous iridium‑hafnium diffusion coating was fabricated using the metalliding process in a molten salt of LiF-HfF 4 at relatively low temperatures to improve the oxidation resistance of pure iridium under extreme operating conditions. The phase composition and morphology of the diffusion coatings prepared at different …

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The toxicologic and pharmacologic effects of hafnium salts

Abstract. The toxicology and pharmacology of hafnium salts have been investigated. Acute intraperitoneal toxicity of hafnyl chloride is of the delayed type with an LD 50 per 7 days of 112 (93.3–134.4) mg/kg. Chronic feeding for 90 days at levels of 1.0, 0.1, and 0.01% of the diet produced liver changes at the 1.0% level.

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Deposition of Titanium, Zirconium and Hafnium Diboride

Deposition of Titanium, Zirconium and Hafnium Diboride Coatings by High-Temperature Electrochemical Synthesis from Chloro-Fluoride Melts ... (1993), in Proc. of the Int. Symp. on Molten Salts Chemistry and Technology, The Electrochemical Society Proceedings Series, Pennington, NJ 93–9, 584–599,

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Direct ester condensation from a 1:1 mixture of

We first investigated the catalytic activities of various metal salts (10 mol%) which promote the model reaction of 4-phenylbutyric acid (1 equiv.) with benzyl alcohol (1 equiv.) in toluene at reflux with the removal of water (calcium hydride in a Soxhlet thimble) for 1.5 h (condition A in Table 1).Both ZrCl 4 3m,n and HfCl 4 were highly effective …

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Direct Condensation of Carboxylic Acids with Alcohols …

achieved with the use of hafnium(IV) salts, such as commercially available hafnium(IV) chloride and hafnium(IV) tert-butoxide. The present method can be applied to direct polyesterification operations. The replacement of current chemical process-ing with more environmentally benign alter-natives is an increasingly attractive subject (1).

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Solid-State Synthesis and Characterization of Hafnium Diboride

Abstract. Hafnium diboride (HfB 2) nanoparticles have been prepared by a solid-state reaction of hafnium dioxide (HfO 2), metallic magnesium (Mg) and sodium borohydride (NaBH 4) at 700°C in an autoclave.The structure and morphology of the obtained product are investigated by X-ray powder diffraction (XRD), transmission …

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The toxicologic and pharmacologic effects of hafnium salts

It is difficult to be certain whether such effects were produced by hafnium or by some impurity, because the exact purity of the salts used is unknown. Therefore, we have …

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Hafnium powder, -325 mesh, 99.6% (metals basis excluding Zr), …

Shop Hafnium powder, -325 mesh, 99.6% (metals basis excluding Zr), Zr nominal 2-3.5%, Thermo Scientific Chemicals at Fishersci

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Hafnium Hydroxide | AMERICAN ELEMENTS

72 Hf 178.480000000 Hafnium. See more Hafnium products. Hafnium (atomic symbol: Hf, atomic number: 72) is a Block D, Group 4, Period 6 element with an atomic weight of 178.49. The number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electron configuration is [Xe] 4f 14 5d 2 6s 2. The hafnium atom has a radius of 159 pm ...

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Halides, oxyhalides, and salts of halogen complexes of titanium

Responsibility volume editor, Jiri Hála. Imprint Oxford ; New York : Pergamon Press, c1989. Physical description xxxvi, 327 p. : ill. ; 28 cm. Series

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RAMAN SPECTROSCOPY AND INORGANIC OXIDIZING …

number of bonds in these two salts, giving them different molecular geometry. As an example, the potassium salts of chlorate and perchlorate are shown below in Figure 1 (red is the chlorate; black is the perchlorate salt). There is suffi cient peak separation and peak shape differences to enable the differentiation of the chlorate and the

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Hafnium salts of dodeca-tungstophosphoric acid catalysts for …

To the best of our knowledge, no detailed study has been reported on hafnium salts of tungstophosphoric acid for organic synthesis. The objective of the …

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Direct ester condensation from a 1:1 mixture of carboxylic acids …

An atom efficient esterification of equimolar amounts of carboxylic acids and alcohols could be achieved using hafnium(IV) or zirconium(IV) salts. These metal salts are highly effective as catalysts for the selective esterification of primary alcohols with carboxylic acids in the presence of secondary alcohols or aromatic alcohols.

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Hafnium oxide, 99%

Leading Manufacturers and suppliers of Hafnium oxide, 99%, India with worldwide shipping. Various grades of quality available suitable for all applications. Low Price!! Best Quality!! ; H 1217 (OTTO) Hafnium oxide, 99% Cas 1 - used in optical coatings, and as a high-κ dielectric in DRAM capacitors and in advanced metal-oxide-semiconductor devices.

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Tetrakis(diethylamido)hafnium(IV) | AMERICAN …

72 Hf 178.480000000 Hafnium. See more Hafnium products. Hafnium (atomic symbol: Hf, atomic number: 72) is a Block D, Group 4, Period 6 element with an atomic weight of 178.49. The number of electrons in …

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Phys. Rev. B 80, 054304 (2009)

Raman spectra of monoclinic hafnium oxide $({text{HfO}}_{2})$ were measured at temperatures up to 1100 K. Raman peak shifts and broadenings are reported. Phonon dynamics calculations were performed with the shell model to obtain the total and partial phonon density of states, and to identify the individual motions of Hf and O atoms …

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The toxicologic and pharmacologic effects of hafnium salts

The toxicology and pharmacology of hafnium salts have been investigated. Acute intraperitoneal toxicity of hafnyl chloride is of the delayed type with an LD 50 per 7 days of 112 (93.3–134.4) mg/kg. Chronic feeding for 90 days at levels of 1.0, 0.1, and 0.01% of the diet produced liver changes at the 1.0% level.

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Low-Melting Ionic Salts | SpringerLink

Low-melting salts, i.e., those melting between 100 and 250 °C but are highly ionic are dealt with here. These include many inorganic salts as well as symmetrical quaternary ammonium and phosphonium salts, the properties of which as liquids are tabulated and discussed. Salt hydrates, whether melting congruently or not, form another …

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Hafnium Acetate | AMERICAN ELEMENTS

Hafnium Acetate is a moderately water soluble crystalline Hafnium source that decomposes to Hafnium oxide on heating. It is generally immediately available in most volumes. All metallic acetates are inorganic salts containing a metal cation and the acetate anion, a univalent (-1 charge) polyatomic ion composed of two carbon atoms ionically …

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Hafnium Sulfate | AMERICAN ELEMENTS

Hafnium (atomic symbol: Hf, atomic number: 72) is a Block D, Group 4, Period 6 element with an atomic weight of 178.49. The number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electron configuration is [Xe] 4f 14 5d 2 6s 2.

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