US4751070A
Expired / Lapsed
US
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Low temperature synthesis
Assignee: Lockheed Martin Corp
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Filing: 1986-04-15
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Granted: 1988-06-14
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Expires: 2006-04-15
Abstract
Abstract Ultrafine particles of ceramic or metallic material are obtained at low temperatures from a nitrate source capable of endothermic decomposition by molecularly combining under a nitrogen atmosphere the nitrate source with an inorganic reducing fuel compound, such as hydrazine, to provide a chemical precursor for the ceramic or metallic material and then exothermically decomposing the precursor in a controlled atmosphere by heating to a temperature up to about 200 DEG C. below the endothermic decomposition temperature of the nitrate source. The nitrate source is a metal nitrate or a mixture of nitrate salts. Ferrite particles are recovered when the nitrate source is a mixture of nitrate salts containing ferric nitrate in a 2:1 molar ratio with at least one additional metal nitrate.
Inventors
- 👤 Vencatesh R. Pai Verneker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:24
CPC Classifications
C; C22; C22B; C22B5/00; C01; C01F; C01F7/00; C01F7/02; C01G; C01G25/00; C01G25/02; C01G49/00; C01G49/009; C01G49/02; C01G49/06; C22B34/00; C22B34/10; C22B34/12; C22B34/129; G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70652; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/34; H01F1/36; C01P; C01P2006/00; C01P2006/42
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
117 words
A method for synthesizing sub-micron particles of ceramic materials from a non-aqueous nitrate source capable of endothermic decomposition, said nitrate source comprising at least one nitrate salt of iron, cobalt, nickel, manganese, chromium, titanium, zirconium, aluminum, magnesium, zinc, cadmium, copper, boron, or silicon, said method comprising the steps of molecularly combining said nitrate source with an inorganic reducing fuel selected from hydrazine and hydrazine hydrate, under a nitrogen atmosphere, to provide a metal nitrate hydrazinate coordination compound chemical precursor of said ceramic material, and thereafter exothermically decomposing said precursor under an atmosphere selected from nitrogen, hydrogen, or vacuum by heating to a temperature up to about 200° C. below the endothermic decomposition temperature of said nitrate source.
Claim 2
Independent Claim
117 words
A method for synthesizing sub-micron particles of ceramic materials from a non-aqueous nitrate source capable of endothermic decomposition, said nitrate source comprising at least one nitrate salt of iron, cobalt, nickel, manganese, chromium, titanium, zirconium, aluminum, magnesium, zinc, cadmium, copper, boron, or silicon, said method comprising the steps of molecularly combining said nitrate source with an inorganic reducing fuel selected from hydrazine and hydrazine hydrate, under a nitrogen atmosphere, to provide a metal nitrate hydrazinate coordination compound chemical precursor of said ceramic material, and thereafter exothermically decomposing said precursor under an atmosphere selected from nitrogen, hydrogen, or vacuum by heating to a temperature up to about 200° C. below the endothermic decomposition temperature of said nitrate source.
Claim 3
Dependent Claim
19 words
The method according to claim 1 wherein said atmosphere comprises oxygen, and sub-micron particles of the ceramic are recovered.
Claim 4
Dependent Claim
13 words
The method according to claim 2 wherein said nitrate salt is ferric nitrate.
Claim 5
Dependent Claim
13 words
The method according to claim 2 wherein said nitrate salt is aluminum nitrate.
Claim 6
Dependent Claim
17 words
The method according to claim 2 wherein said nitrate salt is selected from zirconium and titanium nitrates.
Claim 7
Dependent Claim
21 words
The method according to claim 2 wherein said nitrate source is a mixture of two or more of said nitrate salts.
Claim 8
Dependent Claim
15 words
The method according to claim 6 wherein one of said nitrate salts is ferric nitrate.
Claim 9
Dependent Claim
23 words
The method according to claim 7 wherein said nitrate salts comprise ferric nitrate, nickel nitrate, and zinc nitrate, in a 4:1:1 molar ratio.
Claim 10
Dependent Claim
16 words
The method according to claim 6 wherein said nitrate salts comprise lead nitrate and titanium nitrate.
Claim 11
Dependent Claim
27 words
A method according to claim 2 wherein said precursor is exothermically decomposed by heating to a temperature up to about 100° C., and said ceramic is iron-containing.
Claim 12
Dependent Claim
17 words
A method according to claim 10 wherein sub-micron particles of γ Fe 2 O 3 are recovered.
Claim 13
Dependent Claim
31 words
The method according to claim 10 wherein said nitrate source is a mixture of nitrate salts containing ferric nitrate in a 2:1 molar ratio with at least one additional metal nitrate.
Claim 14
Dependent Claim
13 words
The method according to claim 12 wherein sub-micron particles of ferrite are recovered.
Claim 15
Dependent Claim
23 words
The method according to claim 13 wherein said nitrate salts comprise ferric nitrate, nickel nitrate and zinc nitrate in a 4:1:1 molar ratio.
Claim 16
Independent Claim
106 words
A method for synthesizing sub-micron ferrite particles from a non-aqueous nitrate source which comprises a mixture of ferric nitrate in a 2:1 molar ratio with at least one additional nitrate salt of iron, cobalt, nickel manganese, chromium, titanium, zirconium, aluminum, magnesium, zinc, cadmium, copper, boron, or silicon, salt method comprising the steps of molecularly combining said nitrate source with an inorganic reducing fuel selected from hydrazine and hydrazine hydrate under a nitrogen atmosphere, to provide a metal nitrate hydrazinate coordination compound chemical precursor for said ferrite, and thereafter exothermically decomposing said precursor in an oxygen-containing atmosphere by heating to a temperature up to about 100° C.
Claim 17
Independent Claim
106 words
A method for synthesizing sub-micron ferrite particles from a non-aqueous nitrate source which comprises a mixture of ferric nitrate in a 2:1 molar ratio with at least one additional nitrate salt of iron, cobalt, nickel manganese, chromium, titanium, zirconium, aluminum, magnesium, zinc, cadmium, copper, boron, or silicon, salt method comprising the steps of molecularly combining said nitrate source with an inorganic reducing fuel selected from hydrazine and hydrazine hydrate under a nitrogen atmosphere, to provide a metal nitrate hydrazinate coordination compound chemical precursor for said ferrite, and thereafter exothermically decomposing said precursor in an oxygen-containing atmosphere by heating to a temperature up to about 100° C.
Claim 18
Dependent Claim
25 words
The method according to claim 15 wherein said nitrate source is a mixture of ferrie nitrate, nickel nitrate, and zinc nitrate in a 4:1:1 ratio.
Claim 19
Independent Claim
109 words
A method for synthesizing sub-micron particles of metallic material from a non-aqueous nitrate source capable of endothermic decomposition, said nitrate source comprising at least one nitrate salt of iron, cobalt, nickel, manganese, chromium, titanium, zirconium, aluminum, magnesium, zinc, cadmium, copper, boron or silicon, said method comprising the steps of molecularly combining said nitrate source with hydrazine hydrate under a nitrogen atmosphere, to provide a metal nitrate hydrazinate coordination compound chemical precursor for said metallic material, and thereafter exothermically decomposing said precursor under an atmosphere selected from nitrogen, hydrogen, or vacuum by heating to a temperature up to about 200° C. below the endothermic decomposition temperature of said nitrate source.
Claim 20
Independent Claim
109 words
A method for synthesizing sub-micron particles of metallic material from a non-aqueous nitrate source capable of endothermic decomposition, said nitrate source comprising at least one nitrate salt of iron, cobalt, nickel, manganese, chromium, titanium, zirconium, aluminum, magnesium, zinc, cadmium, copper, boron or silicon, said method comprising the steps of molecularly combining said nitrate source with hydrazine hydrate under a nitrogen atmosphere, to provide a metal nitrate hydrazinate coordination compound chemical precursor for said metallic material, and thereafter exothermically decomposing said precursor under an atmosphere selected from nitrogen, hydrogen, or vacuum by heating to a temperature up to about 200° C. below the endothermic decomposition temperature of said nitrate source.
Claim 21
Dependent Claim
21 words
A method according to claim 17 wherein said nitrate source is a mixture of two or more of said nitrate salts.
Claim 22
Dependent Claim
20 words
The method according to claim 18 wherein said nitrate salts include ferric nitrate and at least one additional metal nitrate.
Claim 23
Dependent Claim
16 words
The method according to claim 19 wherein said nitrate salts comprise ferric nitrate and boron nitrate.
Claim 24
Dependent Claim
16 words
The method according to claim 19 wherein said nitrate salts comprise ferric nitrate and magnesium nitrate.
Claim 25
Independent Claim
84 words
A method for synthesizing sub-micron particles of an iron-containing metallic material from a non-aqueous nitrate source which includes ferric nitrate, the method including the steps of molecularly combining said nitrate source with an inorganic reducing fuel selected from hydrazine and hydrazine hydrate under a nitrogen atomosphere, to provide a metal nitrate hydrazinate coordination compound chemical precursor for said metallic material, and thereafter exothermically decomposing aid precursor an atmosphere selected from hydrogen-containing, nitrogen-containing, and vacuum, by heating to a temperature up to about 100° C.
Claim 26
Independent Claim
84 words
A method for synthesizing sub-micron particles of an iron-containing metallic material from a non-aqueous nitrate source which includes ferric nitrate, the method including the steps of molecularly combining said nitrate source with an inorganic reducing fuel selected from hydrazine and hydrazine hydrate under a nitrogen atomosphere, to provide a metal nitrate hydrazinate coordination compound chemical precursor for said metallic material, and thereafter exothermically decomposing aid precursor an atmosphere selected from hydrogen-containing, nitrogen-containing, and vacuum, by heating to a temperature up to about 100° C.
Claim 27
Dependent Claim
13 words
The method according to claim 22 wherein sub-micron particles of iron are recovered.
Claim 28
Dependent Claim
47 words
The method according to claim 22 wherein said nitrate source is a mixture of nitrate salts containing ferric nitrate in a 21 molar ratio with at least one additional nitrate salt of iron, cobalt, nickel, manganese, chromium, titanium, zirconium, aluminum, magnesium, zinc, cadmium, copper, borom or silicon.
References Cited (Backward Citations)
US4076861A
Cited
US4125474A
Cited
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