GB2448606A - Doped rare-earth oxides - Google Patents
Doped rare-earth oxides Download PDFInfo
- Publication number
- GB2448606A GB2448606A GB0806998A GB0806998A GB2448606A GB 2448606 A GB2448606 A GB 2448606A GB 0806998 A GB0806998 A GB 0806998A GB 0806998 A GB0806998 A GB 0806998A GB 2448606 A GB2448606 A GB 2448606A
- Authority
- GB
- United Kingdom
- Prior art keywords
- mol
- doped
- shows
- rare
- reflectance spectrum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 229910001404 rare earth metal oxide Inorganic materials 0.000 title claims abstract description 7
- 239000000463 material Substances 0.000 claims abstract description 23
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 13
- 229910052689 Holmium Inorganic materials 0.000 claims abstract description 12
- 229910052779 Neodymium Inorganic materials 0.000 claims abstract description 6
- 229910052691 Erbium Inorganic materials 0.000 claims abstract description 5
- 239000002019 doping agent Substances 0.000 claims description 13
- 150000002910 rare earth metals Chemical class 0.000 claims description 5
- 238000000985 reflectance spectrum Methods 0.000 description 19
- 238000010521 absorption reaction Methods 0.000 description 11
- JYTUFVYWTIKZGR-UHFFFAOYSA-N holmium oxide Inorganic materials [O][Ho]O[Ho][O] JYTUFVYWTIKZGR-UHFFFAOYSA-N 0.000 description 9
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium oxide Inorganic materials [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 description 8
- KJZYNXUDTRRSPN-UHFFFAOYSA-N holmium atom Chemical compound [Ho] KJZYNXUDTRRSPN-UHFFFAOYSA-N 0.000 description 7
- 230000031700 light absorption Effects 0.000 description 6
- 229910019792 NbO4 Inorganic materials 0.000 description 2
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 229910052727 yttrium Inorganic materials 0.000 description 2
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 2
- 101150093961 ANP32A gene Proteins 0.000 description 1
- 235000005811 Viola adunca Nutrition 0.000 description 1
- 240000009038 Viola odorata Species 0.000 description 1
- 235000013487 Viola odorata Nutrition 0.000 description 1
- 235000002254 Viola papilionacea Nutrition 0.000 description 1
- 238000002835 absorbance Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- OWCYYNSBGXMRQN-UHFFFAOYSA-N holmium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Ho+3].[Ho+3] OWCYYNSBGXMRQN-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 238000001429 visible spectrum Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
- B42D25/29—Securities; Bank notes
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
- G03G21/04—Preventing copies being made of an original
- G03G21/043—Preventing copies being made of an original by using an original which is not reproducible or only reproducible with a different appearence, e.g. originals with a photochromic layer or a colour background
-
- C01F17/0043—
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F17/00—Compounds of rare earth metals
- C01F17/20—Compounds containing only rare earth metals as the metal element
- C01F17/206—Compounds containing only rare earth metals as the metal element oxide or hydroxide being the only anion
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D11/00—Inks
- C09D11/02—Printing inks
- C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/06—Luminescent, e.g. electroluminescent, chemiluminescent materials containing organic luminescent materials
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
- D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
- D21H21/44—Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
- D21H21/48—Elements suited for physical verification, e.g. by irradiation
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2211/00—Chemical nature of organic luminescent or tenebrescent compounds
- C09K2211/10—Non-macromolecular compounds
- C09K2211/1018—Heterocyclic compounds
- C09K2211/1025—Heterocyclic compounds characterised by ligands
- C09K2211/1074—Heterocyclic compounds characterised by ligands containing more than three nitrogen atoms as heteroatoms
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2211/00—Chemical nature of organic luminescent or tenebrescent compounds
- C09K2211/18—Metal complexes
- C09K2211/187—Metal complexes of the iron group metals, i.e. Fe, Co or Ni
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2211/00—Chemical nature of organic luminescent or tenebrescent compounds
- C09K2211/18—Metal complexes
- C09K2211/188—Metal complexes of other metals not provided for in one of the previous groups
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G2215/00—Apparatus for electrophotographic processes
- G03G2215/00172—Apparatus for electrophotographic processes relative to the original handling
- G03G2215/00206—Original medium
- G03G2215/00299—Confidential, e.g. secret documents
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Business, Economics & Management (AREA)
- Geology (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- General Chemical & Material Sciences (AREA)
- Accounting & Taxation (AREA)
- Finance (AREA)
- Wood Science & Technology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Luminescent Compositions (AREA)
- Facsimile Scanning Arrangements (AREA)
- Printing Methods (AREA)
- Developing Agents For Electrophotography (AREA)
- Glass Compositions (AREA)
- Cleaning In Electrography (AREA)
Abstract
A material comprising YNbO4 Y2WO6 doped with from 0.5 to 20 mol% of a rare earth element, or oxide thereof, selected Er, Nd and Ho.
Description
Title: Improvements in Rare-Earth-based Materials
Field of the Invention
The invention relates to certain rare-earth-based materials.
Background to the Invention
It is known that certain rare earth oxides are capable of selectively absorbing broadband wavelengths of light incident upon them. This property can result in these materials appearing as one colour in daylight and appearing as another colour under synthetic white light. This colour altering property can be of utility, for example to indicate when copying of a document of value has taken place. However, one drawback of these materials is that they are quite costly.
Summary of the Invention
The invention relates to YNbO4 or Y2W06 doped with from 0.5 to 20 mol % of a rare-earth element, or oxide thereof, selected from Nd, Er and Ho.
The doped materials according to the invention surprisingly retains, or even enhances, the light absorption properties of the rare-earth element or its oxide. This enables the rare-earth elements to be used at much lower levels, and thus significantly reducing cost for applications where their light absorption properties are of benefit.
It is generally known that certain rare-earth elements have light absorption bands in the visible spectrum. This property of rare-earth elements may be exploited, for example to indicate when copying of a document of value has taken place, depending on the nature of the incident light.
When rare-earth elements are doped into lattices it is often the case that the properties of the doped lattice are significantly different to those of the undoped lattice or of the dopant.
This combination of particular lattices with small amounts of particular rare-earth dopants can result in a doped material having similar selective light absorption properties to that manifested by the rare-earth oxides, even at low levels of doping.
Preferably the rare-earth dopants are selected from Nd and Ho. Thus, preferred doped materials are YNbO4: Nd; YNbO4: Ho, Y2W06:Nd and Y2W06: Ho.
The dopant is present at from 0.5 to 20 mol %, based on the amount of yttrium in the material. For example, the material (Yo.9Hoo1)Nb04 has 10 mol % doped holmium.
It has been found that for the lattices according to the invention, the amount of dopant can be reduced significantly without noticeable deterioration in the selective light absorption properties when compared to a rare earth oxide also exhibiting selective light absorption.
Thus, it is preferred that the dopant is present at a level of from 0.5 to 10.0 mol %, more preferably from 0.5 to 5.0 mol % and most preferably from 0.3 to 3.0 mol %.
The invention will now be illustrated by way of example, with reference to the following figures, in which: Figure 1 shows the reflectance spectrum of the dopant Ho203.
Figure 2 shows the reflectance spectrum of the dopant Nd203.
Figure 3 shows the reflectance spectrum of the dopant Er203.
Figure 4 shows the reflectance spectrum of the lattice YNbO4.
Figure 5 shows the reflectance spectrum of (Yo.99Hoo 01)Nb04.
Figure 6 shows the reflectance spectrum of(Yo.9iHoo.03)Nb04.
Figure 7 shows the reflectance spectrum of(Yo.9Hoo1)Nb04.
Figure 8 shows the reflectance spectrum of (Yo.99Ndo.01)Nb04.
Figure 9 shows the reflectance spectrum of(Yo.97Nd0.03)Nb04.
Figure 10 shows the reflectance spectrum of(Yo99Ero.01)Nb04.
Figure 11 shows the reflectance spectrum of(Y091Er003)Nb04.
Figure 12 shows the reflectance spectrum of (Yo 9Ero.1)Nb04.
Figure 13 shows the reflectance spectrum of (Yj.9sHoo.02)03.
Figure 14 shows the reflectance spectrum of(Y1.8Ho02)03.
Examples
Reflectance studies on the following materials have been carried out using light emission in the 200-850nm range: Ho203, Nd203, (Y1..Ho)NbO4, (Yi.Nd)NbO4 and undoped YN'b04, using a Perkin-Elmer Lambda 650S UV/visible spectrometer. All reflectance measurements were zero corrected against a Labsphere certified reflectance standard.
The reflectance spectra of Ho203 (Rhone-Poulenc, 99.9%), and Nd203 (Aldrich 99.9%) and Er203 (Rhone-Poulenc, 99.0%) are presented in Figures 1,2 and 3 respectively.
Figure 1 shows that Ho203 has absorption bands between -440-470nm and -535-555nm, which are where the blue and green emission bands of "cool white" of a fluorescent lanp occurs (having main excitation wavelengths at 436nm, 546nm and 612nm). However, Ho203 is highly reflective at -612nm which coincides with the fluorescent lamp red emission band, which explains the pinkish-red appearance of the body colour of holmium oxide under fluorescent lighting.
Figure 2 shows that Nd203 has absorption bands overlapping with the red and green light from fluorescent lamps but reflects the blue light emitted by the lamp. Neodymium oxide has a blue-violet body colour when observed under fluorescent lighting.
Figure 3 shows that Er203 has absorption band maxima at around 520nm and 650nm, in the visible range.
The body colour of Ho203*, Nd203 and Er203 appeared to be whitish when viewed in sunlight. This is due to the broad wavelength range emission of sunlight.
Figure 4 shows the reflectance spectrum of the undoped lattice YNbO4. It can be seen that there are no significant absorption bands in the visible region.
A YNb04 lattice was doped with 1.0, 3.0 and 10.0 mol % of holmium, and the reflectance spectra of the resulting doped materials were assessed. The results are shown in Figures 5 to 7. It can be seen that the visible absorption peaks of Ho203 are largely preserved, even at doping levels as low as 1.0 mcI %. At 10.0 mol % the absorbance bands are even more pronounced than for the pure Ho203 material.
A YNbO4 lattice was doped with 1.0% and 3.0% of neodynium and the reflectance spectra of the doped materials was assessed. The results are shown in Figures 8 and 9. It can be seen that the visible absorption peaks of Nd203 are largely preserved, even at doping levels aslowas 1.Omol%.
A YNbO4 lattice was doped with 1.0, 3.0 and 10.0 mol % of erbium, and the reflectance spectra of the resulting doped materials was assessed. The results are shown in Figures 10 to 12. It can be seen that the absorption bands of erbium are suppressed at lower doping levels. However at 10.0 mol % (Figure 12) the absorption bands are largely preserved. The 10.0 mol % doped material appeared lavender-purple under a Canoscan LJDE 80 light source, generated by LEDs with main excitation wavelengths of 465mn, 525nm and 635nm, whilst appearing whitish under daylight.
A Y2W06 lattice was doped with holmium at a level of 10 mol %. The doped material appeared pink under fluorescent light, whilst appearing whitish under daylight. This indicates that the selective absorption properties of holmium were preserved.
In a comparative example, a Y203 lattice was doped with 1.0 and 10.0 mol % holmium and 10.0 mol % neodymium. The results for holmium are shown in Figures 13 and 14. In general the absorption bands of holmium can be seen to be suppressed. Although some absorption bands are preserved at 10.0 mol % (see Figure 14), this is to a much lesser extent than with the yttrium-based lattices according to the invention (see Figure 7). No noticeable colour change between daylight and a synthetic white light, such as a fluorescent cool white' light could be seen, even at 10.0 mol % doping.
Claims (6)
- Claims 1. A material comprising YNbO4 or Y2W06 lattice doped with from0.5 to 20.0 mol % of a rare-earth element, or oxide thereof, selected from Er, Nd and Ho.
- 2. A material according to claim 1, wherein the rare-earth dopant is selected from Nd and Ho.
- 3. A material according to claim I or claim 2, wherein the lattice is YNbQ4.
- 4. A material according to any one of the preceding claims, wherein the dopant is present at from 0.5 to 10.0 mol %.
- 5. A material according to claim 4, wherein the dopant is present at from 0.5 to S.Omol%.
- 6. A material according to claim 5, wherein the dopant is present at from 0.5 to 3.0 mol %.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB0707420.6A GB0707420D0 (en) | 2007-04-18 | 2007-04-18 | Copy-protected documents |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0806998D0 GB0806998D0 (en) | 2008-05-21 |
| GB2448606A true GB2448606A (en) | 2008-10-22 |
Family
ID=38116888
Family Applications (6)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0707420.6A Ceased GB0707420D0 (en) | 2007-04-18 | 2007-04-18 | Copy-protected documents |
| GB0806998A Withdrawn GB2448606A (en) | 2007-04-18 | 2008-04-17 | Doped rare-earth oxides |
| GB0806996.5A Expired - Fee Related GB2448605B (en) | 2007-04-18 | 2008-04-17 | Copy-protected documents |
| GB0806995.7A Expired - Fee Related GB2448604B (en) | 2007-04-18 | 2008-04-17 | Copy-protected documents |
| GB1200640.9A Expired - Fee Related GB2484233B (en) | 2007-04-18 | 2008-04-17 | Improvements in rare-earth-based materials |
| GB0806994.0A Expired - Fee Related GB2448603B (en) | 2007-04-18 | 2008-04-17 | Copy-protected documents |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0707420.6A Ceased GB0707420D0 (en) | 2007-04-18 | 2007-04-18 | Copy-protected documents |
Family Applications After (4)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0806996.5A Expired - Fee Related GB2448605B (en) | 2007-04-18 | 2008-04-17 | Copy-protected documents |
| GB0806995.7A Expired - Fee Related GB2448604B (en) | 2007-04-18 | 2008-04-17 | Copy-protected documents |
| GB1200640.9A Expired - Fee Related GB2484233B (en) | 2007-04-18 | 2008-04-17 | Improvements in rare-earth-based materials |
| GB0806994.0A Expired - Fee Related GB2448603B (en) | 2007-04-18 | 2008-04-17 | Copy-protected documents |
Country Status (1)
| Country | Link |
|---|---|
| GB (6) | GB0707420D0 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0918939D0 (en) * | 2009-10-29 | 2009-12-16 | Bank Of England | Security document |
| CN116218525B (en) * | 2023-01-16 | 2024-06-21 | 海南大学 | Thermosensitive up-conversion luminescent material and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3758486A (en) * | 1969-05-13 | 1973-09-11 | Westinghouse Electric Corp | Rare earth niobate composition |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4678322A (en) * | 1986-05-30 | 1987-07-07 | Xerox Corporation | Method and apparatus for the prevention of unauthorized copying of documents |
| US4791449A (en) * | 1986-05-30 | 1988-12-13 | Xerox Corporation | System for prevention of unauthorized copying |
| US5271764A (en) * | 1992-02-12 | 1993-12-21 | Xerox Corporation | Ink compositions |
| JP4378789B2 (en) * | 1999-05-21 | 2009-12-09 | 凸版印刷株式会社 | Anti-counterfeit printed matter |
| US6483576B1 (en) * | 1999-12-10 | 2002-11-19 | Laser Lock Technologies, Inc. | Counterfeit detection system |
| DE10036940A1 (en) * | 2000-07-28 | 2002-02-07 | Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh | Luminescence conversion LED |
| GB0314883D0 (en) * | 2003-06-26 | 2003-07-30 | Ncr Int Inc | Security labelling |
| US20050143249A1 (en) * | 2003-06-26 | 2005-06-30 | Ross Gary A. | Security labels which are difficult to counterfeit |
| CN1239673C (en) * | 2003-10-23 | 2006-02-01 | 北京有色金属研究总院 | Red luminescent powder in use for LED, preparing method and electric light source produced |
| EP1990312A3 (en) * | 2005-10-03 | 2009-09-02 | Sun Chemical Corporation | Security pigments and the process of making thereof |
-
2007
- 2007-04-18 GB GBGB0707420.6A patent/GB0707420D0/en not_active Ceased
-
2008
- 2008-04-17 GB GB0806998A patent/GB2448606A/en not_active Withdrawn
- 2008-04-17 GB GB0806996.5A patent/GB2448605B/en not_active Expired - Fee Related
- 2008-04-17 GB GB0806995.7A patent/GB2448604B/en not_active Expired - Fee Related
- 2008-04-17 GB GB1200640.9A patent/GB2484233B/en not_active Expired - Fee Related
- 2008-04-17 GB GB0806994.0A patent/GB2448603B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3758486A (en) * | 1969-05-13 | 1973-09-11 | Westinghouse Electric Corp | Rare earth niobate composition |
Non-Patent Citations (2)
| Title |
|---|
| Bing Yan, Xiuzhen Xiao (2007) Novel YNbO4:RE3+ (RE=Sm, Dy, Er) microcrystalline phosphors: Chemical co-precipitation synthesis from hybrid precursor and photoluminescent properties. Journal of Alloys and Compounds 433, 251-255. * |
| GA Wesselink, A Bril (1965) Fluorescent properties of trivalent neodymium in lanthanum and yttrium orthoniobates and tantalates. Philips Research Reports 20, 269-277 * |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2448605A (en) | 2008-10-22 |
| GB2484233B (en) | 2012-11-14 |
| GB2448603A (en) | 2008-10-22 |
| GB2448605B (en) | 2012-05-02 |
| GB0806994D0 (en) | 2008-05-21 |
| GB2448604A (en) | 2008-10-22 |
| GB0806998D0 (en) | 2008-05-21 |
| GB2448604B (en) | 2012-05-02 |
| GB2484233A (en) | 2012-04-04 |
| GB0806996D0 (en) | 2008-05-21 |
| GB0707420D0 (en) | 2007-05-23 |
| GB201200640D0 (en) | 2012-02-29 |
| GB2448603B (en) | 2012-05-02 |
| GB0806995D0 (en) | 2008-05-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111878716B (en) | Enhanced color preference LED light source using YAG, nitride, and PFS phosphors | |
| US10946211B2 (en) | Non-melatonin suppressing light source with a CRI that approaches that of white light | |
| RU2634699C1 (en) | Light-emitting module, lamp, illuminator and method of object lighting | |
| Luo et al. | Realizing superior white LEDs with both high R9 and luminous efficacy by using dual red phosphors | |
| EP3204690B1 (en) | Materials and optical components for color filtering in lighting apparatus | |
| CN105702837B (en) | A kind of imitative sunlight spectrum LED light source | |
| WO2007041563A3 (en) | Cerium based phosphor materials for solid-state lighting applications | |
| WO2008019481A1 (en) | Bi-chromatic illumination apparatus | |
| US20150054007A1 (en) | Food Lighting Device and Meat Lighting Device | |
| Ji et al. | Thermally stable phosphor-in-glass for enhancement of characteristic in high power LED applications | |
| Nishiura et al. | Preparation of transparent Ce3+: GdYAG ceramics phosphors for white LED | |
| KR102121266B1 (en) | High-color-rendering white light-emitting device containing near-infrared light component | |
| EP3454390A1 (en) | Method and system for reducing reflection of ambient light in an emissive display | |
| GB2448606A (en) | Doped rare-earth oxides | |
| JP2017222750A (en) | Phosphor, light emitting device and display device | |
| Sontakke et al. | Significance of host׳ s intrinsic absorption band tailing on Ce3+ luminescence quantum yield in borate glass | |
| CN108019634B (en) | White light LED lamp lighting method and LED lighting device | |
| US11242960B2 (en) | Composite material for lighting filtering, lighting apparatus, and method for determining doping concentration or thickness of composite material | |
| TWI510448B (en) | Wideband luminescent materials and white light luminescent materials | |
| JP2006299097A (en) | Light emitting apparatus | |
| KR102295679B1 (en) | Phosphor and light emitting device | |
| KR102002695B1 (en) | Barium-yttrium-orthosilicate fluorescent material for white LED | |
| Fu et al. | White light emission from Tb 3+/Sm 3+ codoped LiYF 4 single crystal excited by UV light | |
| US11862758B2 (en) | Systems and methods for fluoride ceramic phosphors for LED lighting | |
| US11003052B2 (en) | Mobile device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |