US7449128B2
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US
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Scintillator nanoparticles and method of making
Assignee: General Electric Co
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Filing: 2004-06-21
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Granted: 2008-11-11
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Expires: 2024-06-21
Abstract
Abstract A nanomaterial comprising a plurality of nanoparticles. The plurality of nanoparticles includes at least one dopant and at least one of a metal oxide, a metal phosphate, a metal silicate, a metal hafnate, a metal aluminate, and combinations thereof. The metal is one of an alkali earth metal, a lanthanide, and a transition metal. The plurality of nanoparticles is formed by forming a homogenized precursor solution of at least one metal precursor and at least one dopant precursor, adding a fuel and optionally at least one of a phosphate source, a silicate source, a hafnate source, and an aluminate source to the precursor solution, removing water from the precursor solution to leave a reaction concentrate, and igniting the reaction concentrate to form a powder comprising the nanomaterial. In one embodiment, the nanomaterial is a scintillator material.
Inventors
- 👤 Kalaga Murali Krishna
- 👤 Sergio Paulo Martins Loureiro
- 👤 Mohan Manoharan
- 👤 Geetha Karavoor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:54
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7767; C09K11/7769; C09K11/7783; C09K11/7784; C09K11/7787; Y; Y10; Y10S; Y10S977/00; Y10S977/70; Y10S977/773; Y10S977/775; Y10S977/776; Y10S977/811
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
154 words
A method of making a scintillator nanomaterial comprising a plurality of nanoparticles, wherein said plurality of nanoparticles comprises at least one dopant and one of a metal oxide, a metal phosphate, a metal silicate, a metal hafnate, a metal aluminate, and combinations thereof, wherein said metal is one of an alkali earth metal, a lanthanide, and a transition metal, the method comprising the steps of: (a) providing at least one metal precursor and at least one dopant precursor; (b) forming a homogenized precursor solution of the at least one metal precursor and the at least one dopant precursor; (c) adding a fuel and optionally at least one of a phosphate source, a silicate source, a hafnate source, and an aluminate source to the homogenized precursor solution; (d) removing water from the homogenized precursor solution to leave a reaction concentrate; and (e) igniting the reaction concentrate to form a powder comprising said plurality of nanoparticles.
Claim 2
Independent Claim
154 words
A method of making a scintillator nanomaterial comprising a plurality of nanoparticles, wherein said plurality of nanoparticles comprises at least one dopant and one of a metal oxide, a metal phosphate, a metal silicate, a metal hafnate, a metal aluminate, and combinations thereof, wherein said metal is one of an alkali earth metal, a lanthanide, and a transition metal, the method comprising the steps of: (a) providing at least one metal precursor and at least one dopant precursor; (b) forming a homogenized precursor solution of the at least one metal precursor and the at least one dopant precursor; (c) adding a fuel and optionally at least one of a phosphate source, a silicate source, a hafnate source, and an aluminate source to the homogenized precursor solution; (d) removing water from the homogenized precursor solution to leave a reaction concentrate; and (e) igniting the reaction concentrate to form a powder comprising said plurality of nanoparticles.
Claim 3
Dependent Claim
28 words
The method according to claim 1 , wherein the scintillator nanomaterial is selected from the group consisting of strontium hafnate, yttrium gadolinium oxide, gadolinium aluminate, and combinations thereof.
Claim 4
Dependent Claim
28 words
The method according to claim 1 , wherein the plurality of nanoparticles has a mean particle size in a range from about 10 nm to about 300 nm.
Claim 5
Dependent Claim
28 words
The method according to claim 3 , wherein the plurality of nanopaiticles has a mean particle size in a range from about 10 nm to about 100 nm.
Claim 6
Dependent Claim
28 words
The method according to claim 4 , wherein the plurality of nanoparticles has a mean particle size in a range from about 20 nm to about 60 nm.
Claim 7
Dependent Claim
35 words
The method according to claim 1 , wherein the transition metal is one of vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, ruthenium, rhodium, rhenium, osmium, iridium, hafnium, tantalum, and combinations thereof.
Claim 8
Dependent Claim
31 words
The method according to claim 1 , wherein the lanthanide is one of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, yttrium, and combinations thereof.
Claim 9
Dependent Claim
21 words
The method according to claim 1 , wherein the alkali earth metal is one of calcium, strontium, barium, and combinations thereof.
Claim 10
Dependent Claim
24 words
The method according to claim 1 , wherein said phosphate source is one of di-ammonium hydrogen phosphate, phosphoric acid, boron phosphate, and combinations thereof.
Claim 11
Dependent Claim
21 words
The method according to claim 1 , wherein said silicate source is one of tetraethyl orthosilicate, tetramethyl orthosilicate, and combinations thereof.
Claim 12
Dependent Claim
25 words
The method according to claim 1 , wherein said hafnate source is one of hafnium chloride, hafnium nitrate, hafnium carbonate, hafnium acetate, and combinations thereof.
Claim 13
Dependent Claim
25 words
The method according to claim 1 , wherein said aluminate source is one of aluminum chloride, aluminum nitrate, aluminum carbonate, aluminum acetate, and combinations thereof.
Claim 14
Dependent Claim
14 words
The method according to claim 1 , wherein the fuel is a carbon source.
Claim 15
Dependent Claim
24 words
The method according to claim 13 , wherein the carbon source is selected from the group consisting of urea, glycine, hydrazine, and combinations thereof.
Claim 16
Dependent Claim
18 words
The method according to claim 1 , wherein the plurality of nanoparticles are optically transparent to visible light.
Claim 17
Dependent Claim
33 words
The method according to claim 1 , wherein the metal precursor is selected from the group consisting of a metal nitrate, a metal oxide, a metal acetate, a metal carbonate, and combinations thereof.
Claim 18
Dependent Claim
46 words
The method according to claim 1 , wherein the dopant precursor is a compound selected from the group consisting of cerium, lutetium, europium, terbium, and combinations thereof and is selected from the group consisting of an oxide, an acetate, a carbonate, a nitrate, and combinations thereof.
Claim 19
Dependent Claim
61 words
The method according to claim 1 , wherein the step of forming a homogenized precursor solution of at least one metal precursor and at least one dopant precursor comprises: (a) reacting the at least one metal precursor and the at least one dopant precursor with a nitrate source to form a metal nitrate; and (b) dissolving the metal nitrate in water.
Claim 20
Dependent Claim
21 words
The method according to claim 18 , wherein the nitrate source comprises at least one of nitric acid and ammonium nitrate.
Claim 21
Dependent Claim
31 words
The method according to claim 1 , wherein the homogenized precursor solution is formed by dissolving the at least one metal precursor and the at least one dopant precursor in water.
Claim 22
Dependent Claim
24 words
The method according to claim 1 , wherein the homogenized precursor solution has a pH in a range from about 0.5 to about 5.
Claim 23
Dependent Claim
20 words
The method according to claim 21 , wherein the pH is in a range from about 1 to about 3.5.
Claim 24
Dependent Claim
33 words
The method according to claim 1 , wherein the fuel and the metal nitrate are present in said homogenized precursor solution, in a ratio in a range from about 1:2 to about 2:1.
Claim 25
Dependent Claim
21 words
The method according to claim 1 , wherein the water is removed from the homogenized precursor solution using a microwave oven.
Claim 26
Dependent Claim
20 words
The method according to claim 1 , wherein the water is removed from the homogenized precursor solution using a furnace.
Claim 27
Dependent Claim
36 words
The method according to claim 1 , wherein the water is removed from the homogenized precursor solution using a hot plate, heated to a temperature in a range from about 200° C. to about 500° C.
Claim 28
Dependent Claim
22 words
The method according to claim 26 , wherein the temperature is in a range from about 200° C. to about 300° C.
Claim 29
Dependent Claim
15 words
The method according to claim 1 , further comprising the step of homogenizing the powder.
Claim 30
Dependent Claim
24 words
The method according to claim 28 , wherein the step of homogenizing the powder comprises at least one of grinding and milling the powder.
Claim 31
Dependent Claim
46 words
The method according to claim 1 further comprising the step of stabilizing said powder, wherein the step of stabilizing comprises heating said powder to a temperature in a range from about 600° C. to about 1200° C., in a controlled atmosphere for a period of time.
Claim 32
Dependent Claim
23 words
The method according to claim 30 , wherein the predetermined temperature is in a range from about 800° C. to about 1000° C.
Claim 33
Dependent Claim
24 words
The method according to claim 30 , wherein the controlled atmosphere is selected from the group consisting of air, nitrogen, hydrogen, and combinations thereof.
Claim 34
Dependent Claim
23 words
The method according to claim 30 , wherein the period of time is in a range from about 1 hour to 12 hours.
Claim 35
Dependent Claim
23 words
The method according to claim 33 , wherein said period of time is in a range from about 1 hour to 6 hours.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2011-11-11 | 2012-05-12 | 2012-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2015-11-11 | 2016-05-12 | 2016-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2019-11-11 | 2020-05-12 | 2020-11-11 | $7700.00 | Window Closed / Lapsed |