CA1082910A - Luminescent screen - Google Patents
Luminescent screenInfo
- Publication number
- CA1082910A CA1082910A CA249,872A CA249872A CA1082910A CA 1082910 A CA1082910 A CA 1082910A CA 249872 A CA249872 A CA 249872A CA 1082910 A CA1082910 A CA 1082910A
- Authority
- CA
- Canada
- Prior art keywords
- luminescent
- silicate
- materials
- formula
- mixture
- 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.)
- Expired
Links
Classifications
-
- 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
- C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
- C09K11/7728—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
- C09K11/77344—Aluminosilicates
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Luminescent Compositions (AREA)
Abstract
ABSTRACT:
A luminescent silicate activated by bivalent europium. The silicate is a fluorophlogopite of K, Sr and/or Ba. Preference is given to silicates which are defined by the formula K1-x-pMex-qEup+qMg3Al1+x+pSi3-x-pO10F2, in which Me = Sr, Ba and 0 ? x ? 1 and 0.01 ? p+q ? 0.25.
The silicates have a narrow-band emission with maximum at 360 to 390 nm.
A luminescent silicate activated by bivalent europium. The silicate is a fluorophlogopite of K, Sr and/or Ba. Preference is given to silicates which are defined by the formula K1-x-pMex-qEup+qMg3Al1+x+pSi3-x-pO10F2, in which Me = Sr, Ba and 0 ? x ? 1 and 0.01 ? p+q ? 0.25.
The silicates have a narrow-band emission with maximum at 360 to 390 nm.
Description
108'~910 The invention relates to a luminescent screen provided with a luminescent silicate activated by bivalent europium. Furthermore the invention relates to a mercury vapour discharge lamp provided with such a screen and to the luminescent silicate itself.
Activating silicates by bivalent europium is known and may yield efficient luminescent materials. Our Canadian Patent 880,801, which issued on September 14, 1971, for ex-ample, describes alklaine earth magnesium silicates which are defined by the formula M'2MgSi207 (M' = Ca, Sr, Ba). If part of the alkaline earth metal designated by M' is replaced - by bivalent europium, luminescent materials are obtained whose spectral energy distribution of the emitted radiation consists of a band with a maximum in the wave range of 440 to 540 nm. From our Canadian Patent 895,779, which issued on March 21, 1972, alkaline earth silicates activated by bivalent europium are known which are defined by the for- :
mula BaxSryEupSi205 (x+y+p = 1). When excited by ultra-violet radiation these materials emit in a band with a maximum at 490-505 nm. Our Canadian Patent 1,000,046, which issued on November 23, 1976, describes alkaline earth al-uminium silicates activated by bivalent europium, in which a small part of the alkaline earth metal is replaced by magnesium. The host lattice of these materials, which be-long to the groups of the celdspars, satisfies the formula M"A12Si208 (M" = Ca, Sr, Ba, Mg). The emission band of these luminescent silicates has its maximum value in the wave range of 400 to 460 nm.
For many practical applications it is desir-able to have the disposal of luminescent materials having
Activating silicates by bivalent europium is known and may yield efficient luminescent materials. Our Canadian Patent 880,801, which issued on September 14, 1971, for ex-ample, describes alklaine earth magnesium silicates which are defined by the formula M'2MgSi207 (M' = Ca, Sr, Ba). If part of the alkaline earth metal designated by M' is replaced - by bivalent europium, luminescent materials are obtained whose spectral energy distribution of the emitted radiation consists of a band with a maximum in the wave range of 440 to 540 nm. From our Canadian Patent 895,779, which issued on March 21, 1972, alkaline earth silicates activated by bivalent europium are known which are defined by the for- :
mula BaxSryEupSi205 (x+y+p = 1). When excited by ultra-violet radiation these materials emit in a band with a maximum at 490-505 nm. Our Canadian Patent 1,000,046, which issued on November 23, 1976, describes alkaline earth al-uminium silicates activated by bivalent europium, in which a small part of the alkaline earth metal is replaced by magnesium. The host lattice of these materials, which be-long to the groups of the celdspars, satisfies the formula M"A12Si208 (M" = Ca, Sr, Ba, Mg). The emission band of these luminescent silicates has its maximum value in the wave range of 400 to 460 nm.
For many practical applications it is desir-able to have the disposal of luminescent materials having
- 2 -~~ rl~ 8003 , arl eilicienb emission in a narrow band whose maximum is located in the near ultra-violet part of the spectrum. The 1 object of the invention is to provide such luminescent ' materials.
¦ 5 A luminescent screen according to the invention is provided with a luminescent silicate which is activated by bivalent europium and is characterized in thatthe silicate is a fluorophlogopite of at least one of the elements potassium, strontium and barium, wherein the europium re-places part of at least one of these elements.
As host lattice for a luminescent silicate according to the invention a crystalline substance i8 used which is known as fluorophlogopite. These substances which are known per se, belong to the group of the plate silicates or micas.
They are aluminosilicates of alkaline earth and/or alkali ; metals which furthermore contain fluorine and magnesium. They , are characterized by an (Al + Si): 0-ratio which is equal to 4 : 10 and have a characteristic X-ray diffraction diagram.
It has been surprisingly found that when these fluoro-phlogopites are activated by bivalent europium, very efficient .~, luminescent materials are obtained which can be very well excited by both short-wave and long-wave ultra-violet ra-diation. The emission then obtained consists of a narrow , band (half value width 25 to 50,nm) with a maximum in the spectrum at 360 to 390 nm. These materials luminesce also with other forms of excitation, for example when excited by electrons.
i In the luminescent alkaline earth metal fluoro-., .j ~ ~3-.
~.
PIE~T 8003 8-~l-1976 phlogopites according to the invention, a part of the alkaline earth metal is replaced by the europium activator. They are defined by the formula Me1 qEuqMg3Al2Si201oF2~ where Me is strontium and/or barium and q has a value of 0.01 to 0.25.
It appeared, however, that materials having the same crystal structure can be obtained with a composition which is defecti-ve in the alkaline earth metal. ~harge compensation is then obtained by replacing 2 Al-atoms by 2 Si-atoms for each Me-defect. These materials may be defined by the formula Me1_y_qEUqMg3Al2_2ysi2+2yo1oF2 where y may assume values ~p to appro~imately 0.5 The potassium fluorophlogopite is defined by the ~ rormula KMg3AlSi3010F2. On activation by europium part of j the potassium is replaced by Eu2~. To obtain charge compen-~, 15 sation, part of the Si is replaced by an equal quantity of Al in this replacement. Then these materials are defined by ., i the formula K1 pEupAl1~pSi3 pO1OF2, where p has a value of from 0.01 to 0.25.
Both in the potassium and also in the strontium and .
barium fluorophlogopites, the Si may be replaced entirely or - partly by Ge. Replacing up to 25 mole % of *he Si by Ge affects the luminescent properties of the materials only slightly. Larger quantities of Ge are preferably not used as then the efficiency of the material decreases too much.
It has also proved to be possible to replace in the materials according to the invention the Mg completely or ~ partly by Zn. The Al may also be completely or partly reT
-,~ placed by Si when at the same time equal quantities of Mg .~
. I .
~ PIIN ~003 , 108ZglO
are replaced by Li, for example, KMg2LiSi40~0F2. However, ~ only little advantage is obtained by these replacements ¦ (Mg by Zn and Al by Si) especially not as regards the effi-ciency of the luminescent material.
Preference is given to luminescent fluorophlogopites ~ of K, of Sr and/or Ba, or of mixtures of said elements. These J materials are defined by the general formula K1 x pMex ~
' Eup+q~Ig3~l1+x+psi3 x pO10F2, where ~5e representsat least one s of the elements Sr and Ba~ in which up to 25 moles % of the Si may be replaced by Ge and where ' , O~.x~l 0.01 ~ pfq ~ 0.25 0 ~ p ~ 0.25 o ~ q ~ 0.25 If in this general formula x = 0 is opted ~or (then also q z 0), pure K-fluorophlogopite is obtained. If x = 1 is opted for (then p = 0), pure Sr-and~or Ba-fluorophlogopite ~`
is obtai~ed.
The highest luminous fluxes are obtained with materia~s according to the above general formula when the europium - content, p ~ q, has a value of between 0.05 and 0.15. There-fore such materials are preferred.
Preference is given to alkaline earth metal flu~ro-phlogopites, i.e. the materials according to the above general formula where x = 1 because these materials are most suitable for use in lamps.
The luminescent silicates according to the invention may be applied with much advantage in low pressure mercury ... .
., ~ .
'I
i i ~TIN ~~
8~ 1976 1(~8~910 ,~ .
vapour discharge lamps because they can be excellently excited by the ultra-violet radiation (predominantly 254 nm) generated ; in such lamps. The lamps are particularly suitable for-in-fluencing photochemical processes, for example document reproduction processes and lacquer hardening processes.
~ As the materials according to the invention are also i properly excited by the long-uave ultra-viclet radiation of a high pressure mercury discharge (predominantly 365 nm) they may also be used in high pressure mercury vapour discharge -¦ 10 lamps. An advantage is here that these materials may exhibit j an excellent temperature dependency of the luminous flux.
Namely with this application the luminescent materials must operate at an increased temperature. The ~-fluorophlogopite according to the invention ~ill possesses, for example, at i~ 15 500C a luminous flux which i8 approximately 60% of the , lumlnous flux at room temperature.
The luminescent silicates according to the invention -- may be prepared by starting from a mixture of metal oxides or of compounds which at an increase in temperature supply these oxides, for example carbonates and fluorides. This mix-ture is ubjected for some time to heating at a high tem-., perature which causes the luminescent silicate to be formed.
: . .
; Besides the stoichiometrically required quantities, an excess of fluorine and also an excess of silicate are often used in the mixture, for example as SiF4 or as SiO2 and N~4F, bec~use these elements can disappear partly from the reaction mixture j during heating. The silicates may be formed from the melt, Z heating temperatures above the melting point of the rele~ant .~ .
' ~
Pl~ 8vo3 e 108Z910 8-4-1976 .
;
silicate, for example 50 to 100C higher than the meltin~
point being used. The materials obtained in this manner are crystallized excellently. However, preference is ~ ven . .-i , to a method of preparation in which a solic stace reaction ~3 5 occurs because then a softer powder is obtained which i facilitates processing. In this method of prepa~*ion he~tin~
is done at temperatures below the melting point of the re-~'1 levant silicate, for example 100 to 200~C lower. In most s cases lt is advantageous to effect heating in various steps, :,:
the product being cooled and homogenized in between. As th~
,.
t.; europium must be built into the crystal lattice in bivalent form, it is usually desirable to effect heating, or at least L the last heating operation, in a weakly-reducing atmosphere.
~ By means of X-ray diffraction analyses, the crystal struc-.
ture of the luminescent silicate obtained can be identified and it can be proved that the fluorophlo~opites have been ..
well-formed.
The invention will now be described in greater .
detail with reference to a number of examples and methods.
; 20 EXAMPLE 1:
;. ..
A mixture is made of .
12.4 g K2C03 !.' , ' ' 24.2 g MgO
27.6 g AlF3.3H20 1,0 g Al23 37.8 g SiO2
¦ 5 A luminescent screen according to the invention is provided with a luminescent silicate which is activated by bivalent europium and is characterized in thatthe silicate is a fluorophlogopite of at least one of the elements potassium, strontium and barium, wherein the europium re-places part of at least one of these elements.
As host lattice for a luminescent silicate according to the invention a crystalline substance i8 used which is known as fluorophlogopite. These substances which are known per se, belong to the group of the plate silicates or micas.
They are aluminosilicates of alkaline earth and/or alkali ; metals which furthermore contain fluorine and magnesium. They , are characterized by an (Al + Si): 0-ratio which is equal to 4 : 10 and have a characteristic X-ray diffraction diagram.
It has been surprisingly found that when these fluoro-phlogopites are activated by bivalent europium, very efficient .~, luminescent materials are obtained which can be very well excited by both short-wave and long-wave ultra-violet ra-diation. The emission then obtained consists of a narrow , band (half value width 25 to 50,nm) with a maximum in the spectrum at 360 to 390 nm. These materials luminesce also with other forms of excitation, for example when excited by electrons.
i In the luminescent alkaline earth metal fluoro-., .j ~ ~3-.
~.
PIE~T 8003 8-~l-1976 phlogopites according to the invention, a part of the alkaline earth metal is replaced by the europium activator. They are defined by the formula Me1 qEuqMg3Al2Si201oF2~ where Me is strontium and/or barium and q has a value of 0.01 to 0.25.
It appeared, however, that materials having the same crystal structure can be obtained with a composition which is defecti-ve in the alkaline earth metal. ~harge compensation is then obtained by replacing 2 Al-atoms by 2 Si-atoms for each Me-defect. These materials may be defined by the formula Me1_y_qEUqMg3Al2_2ysi2+2yo1oF2 where y may assume values ~p to appro~imately 0.5 The potassium fluorophlogopite is defined by the ~ rormula KMg3AlSi3010F2. On activation by europium part of j the potassium is replaced by Eu2~. To obtain charge compen-~, 15 sation, part of the Si is replaced by an equal quantity of Al in this replacement. Then these materials are defined by ., i the formula K1 pEupAl1~pSi3 pO1OF2, where p has a value of from 0.01 to 0.25.
Both in the potassium and also in the strontium and .
barium fluorophlogopites, the Si may be replaced entirely or - partly by Ge. Replacing up to 25 mole % of *he Si by Ge affects the luminescent properties of the materials only slightly. Larger quantities of Ge are preferably not used as then the efficiency of the material decreases too much.
It has also proved to be possible to replace in the materials according to the invention the Mg completely or ~ partly by Zn. The Al may also be completely or partly reT
-,~ placed by Si when at the same time equal quantities of Mg .~
. I .
~ PIIN ~003 , 108ZglO
are replaced by Li, for example, KMg2LiSi40~0F2. However, ~ only little advantage is obtained by these replacements ¦ (Mg by Zn and Al by Si) especially not as regards the effi-ciency of the luminescent material.
Preference is given to luminescent fluorophlogopites ~ of K, of Sr and/or Ba, or of mixtures of said elements. These J materials are defined by the general formula K1 x pMex ~
' Eup+q~Ig3~l1+x+psi3 x pO10F2, where ~5e representsat least one s of the elements Sr and Ba~ in which up to 25 moles % of the Si may be replaced by Ge and where ' , O~.x~l 0.01 ~ pfq ~ 0.25 0 ~ p ~ 0.25 o ~ q ~ 0.25 If in this general formula x = 0 is opted ~or (then also q z 0), pure K-fluorophlogopite is obtained. If x = 1 is opted for (then p = 0), pure Sr-and~or Ba-fluorophlogopite ~`
is obtai~ed.
The highest luminous fluxes are obtained with materia~s according to the above general formula when the europium - content, p ~ q, has a value of between 0.05 and 0.15. There-fore such materials are preferred.
Preference is given to alkaline earth metal flu~ro-phlogopites, i.e. the materials according to the above general formula where x = 1 because these materials are most suitable for use in lamps.
The luminescent silicates according to the invention may be applied with much advantage in low pressure mercury ... .
., ~ .
'I
i i ~TIN ~~
8~ 1976 1(~8~910 ,~ .
vapour discharge lamps because they can be excellently excited by the ultra-violet radiation (predominantly 254 nm) generated ; in such lamps. The lamps are particularly suitable for-in-fluencing photochemical processes, for example document reproduction processes and lacquer hardening processes.
~ As the materials according to the invention are also i properly excited by the long-uave ultra-viclet radiation of a high pressure mercury discharge (predominantly 365 nm) they may also be used in high pressure mercury vapour discharge -¦ 10 lamps. An advantage is here that these materials may exhibit j an excellent temperature dependency of the luminous flux.
Namely with this application the luminescent materials must operate at an increased temperature. The ~-fluorophlogopite according to the invention ~ill possesses, for example, at i~ 15 500C a luminous flux which i8 approximately 60% of the , lumlnous flux at room temperature.
The luminescent silicates according to the invention -- may be prepared by starting from a mixture of metal oxides or of compounds which at an increase in temperature supply these oxides, for example carbonates and fluorides. This mix-ture is ubjected for some time to heating at a high tem-., perature which causes the luminescent silicate to be formed.
: . .
; Besides the stoichiometrically required quantities, an excess of fluorine and also an excess of silicate are often used in the mixture, for example as SiF4 or as SiO2 and N~4F, bec~use these elements can disappear partly from the reaction mixture j during heating. The silicates may be formed from the melt, Z heating temperatures above the melting point of the rele~ant .~ .
' ~
Pl~ 8vo3 e 108Z910 8-4-1976 .
;
silicate, for example 50 to 100C higher than the meltin~
point being used. The materials obtained in this manner are crystallized excellently. However, preference is ~ ven . .-i , to a method of preparation in which a solic stace reaction ~3 5 occurs because then a softer powder is obtained which i facilitates processing. In this method of prepa~*ion he~tin~
is done at temperatures below the melting point of the re-~'1 levant silicate, for example 100 to 200~C lower. In most s cases lt is advantageous to effect heating in various steps, :,:
the product being cooled and homogenized in between. As th~
,.
t.; europium must be built into the crystal lattice in bivalent form, it is usually desirable to effect heating, or at least L the last heating operation, in a weakly-reducing atmosphere.
~ By means of X-ray diffraction analyses, the crystal struc-.
ture of the luminescent silicate obtained can be identified and it can be proved that the fluorophlo~opites have been ..
well-formed.
The invention will now be described in greater .
detail with reference to a number of examples and methods.
; 20 EXAMPLE 1:
;. ..
A mixture is made of .
12.4 g K2C03 !.' , ' ' 24.2 g MgO
27.6 g AlF3.3H20 1,0 g Al23 37.8 g SiO2
3-52 g Eu203.
~3 -. ~
Y~ - 7-. ~ .
'I ' i , ~IN 8003 : I 108Z9~ 8-4-197~
This mixture is heated in a closed quartz crucible at 1150C for 1.5 hour in a weakly-reducing atmosphere. After i cooling the product is pulverized and sieved and subse-quently heated at 1150~ for two hours in a weakly-re-ducing atmosphere. The luminescent ailicate thus obtained is defined by the formula KO.gEUo.1Mg3Al1;1S 2.9 10 2 $ ray analysis of the material shows that a potassium fluoro-, phlogopite has benn obtained. When excited by ultra-violet 'j radiation having a wavelength of 254 nm (absorption 96~), the material appears to emit in a band having its maximum at 372 nm and having a half width value of 50,nm. The peak -~ height of the emission band appears to be 115~ of the peak ; height of the known barium disilicate activated by lead, which emits in the same part Or the spectrum and which is used as standard in these measurement. The quantum efficiency of this material according to the invention is 89% (by uay of comparison: the quantum efficiency of the said standard :
is 750 .
EXAMPLE 2:
A mixture of , - 2.030 g SrC03 1.908 g MgO
2.070 g AlF3.3~20 o.765 g Al23 2.059 g SiO2 , 0.264 g EU23 is heated once for 1.5 hour at 1150C in a slightly-reducing atmosphere. The product obtained satisfies the formula .,.
,, , -8-."
., ~lIN X003 ` . ~082~10 SrO 9~-~0.1II~3~l2Si2 10 2 OI stron~iwll Iluoropniogopi~e. ~ hen ~ excited by ultra-violet radiation (254 nm), the material ;i emits in a band with a maximum located at 390 nm, having a ¦ half value width of 39 nm and a peak height of 78% (relative '~¦ 5 to the standard referred to in Example 1).
EXA~LE 3 A mixture of , 35.5 g BaC03 13.8 g MgO
17.15g MgF2 20.4 g Al23 24.5 g SiO2 3.52 g EU23 was heated twice for 2 hours each time at 1150C in a nitro-gen-hydrogen atmoYphere which contained 2% by volume of hydrogen. The starting mixture contains all etements in the stoichiometrically required quantities, recept for fluor which is used with an excess of 30 mole~. The product ob f tained satisfies the formula BaO gEuo 1Mg3Al2Si201o~2 of barium fluorophlogopite. The emission band at 254 nm excitation has a maximum at 375 nm and a peak height of 155%-EX~MPLE 4 ~:
, A mixture is made of 35.5 g BaC03 14.6 g MgO
~, 15-85 g Mg~2 ¦ 22.4 g Al23 ;I 25.7 g S~02 3 ~.52 g Eu203.
'~
9_ 10829~0 8 4-l976 ., .
~his mixture, which contains, in addition to the stoichio-metric quantities, an excess of 20 mol% of fluorine, 5 mole %
of Si and 10 mole% of Al, is heated once for 2 hours at 1150C in a nitrogen-hydrogen mixture which contains 2% by volume of hydrogen. The material obtained has the same formula and the same emission band as the material of Example 3, the peak height being 152%, however.
A mixture is made of 106.6 g BaCO3 ~3.6 g MgO
47.5 g MgF2 73-4 g A12O3 73.5 g SiO2 10.6 g EU23 r Above the stoichiometrically required quantities, this mixture contains an excess of 20 mole % of fluorine and 20 mole% of Al. The mixture is heated for 2 hours at 1150C in air. Sub-:.
sequently the product obtained is subjected to heating for 2 hours at 1150C in a nitrogen-hydrogen mixture which con-` tains 2% by volume of hydrogen. The luminescent material prepared in this manner has the same formula as the material of Example 3 and has an emission band with maximum located . .~
at 385 nm and a peak height of 153%.
, 25 EXAMPLE 6 -~ A mixture of ,, .
. .
r~ 003 ~-4-1 976 108Z~10 .
, 15.8~ g BaCO3 3.52 g EU23 24.2 g MgO
27.6 g AlF3.3II20 36.8 g SiO2 . i i8 heated once for 2 hours at 1150C in a nitrogen-hydrogen mixtur0 which contains 8~ by volume of hydrogen. The;lumines-cent material obtained is a barium fluorophlogopite which is defective in barium and i9 defined by the formula BaO 4Euo 1 Mg3AlSi301oF2. The peak height of the emission band (maximum ~t 375 nm) i~ 110%.
.
.
.' ' " .,-. ..'' . .
~, ''`I
'i .
'~
., . ~
~3 -. ~
Y~ - 7-. ~ .
'I ' i , ~IN 8003 : I 108Z9~ 8-4-197~
This mixture is heated in a closed quartz crucible at 1150C for 1.5 hour in a weakly-reducing atmosphere. After i cooling the product is pulverized and sieved and subse-quently heated at 1150~ for two hours in a weakly-re-ducing atmosphere. The luminescent ailicate thus obtained is defined by the formula KO.gEUo.1Mg3Al1;1S 2.9 10 2 $ ray analysis of the material shows that a potassium fluoro-, phlogopite has benn obtained. When excited by ultra-violet 'j radiation having a wavelength of 254 nm (absorption 96~), the material appears to emit in a band having its maximum at 372 nm and having a half width value of 50,nm. The peak -~ height of the emission band appears to be 115~ of the peak ; height of the known barium disilicate activated by lead, which emits in the same part Or the spectrum and which is used as standard in these measurement. The quantum efficiency of this material according to the invention is 89% (by uay of comparison: the quantum efficiency of the said standard :
is 750 .
EXAMPLE 2:
A mixture of , - 2.030 g SrC03 1.908 g MgO
2.070 g AlF3.3~20 o.765 g Al23 2.059 g SiO2 , 0.264 g EU23 is heated once for 1.5 hour at 1150C in a slightly-reducing atmosphere. The product obtained satisfies the formula .,.
,, , -8-."
., ~lIN X003 ` . ~082~10 SrO 9~-~0.1II~3~l2Si2 10 2 OI stron~iwll Iluoropniogopi~e. ~ hen ~ excited by ultra-violet radiation (254 nm), the material ;i emits in a band with a maximum located at 390 nm, having a ¦ half value width of 39 nm and a peak height of 78% (relative '~¦ 5 to the standard referred to in Example 1).
EXA~LE 3 A mixture of , 35.5 g BaC03 13.8 g MgO
17.15g MgF2 20.4 g Al23 24.5 g SiO2 3.52 g EU23 was heated twice for 2 hours each time at 1150C in a nitro-gen-hydrogen atmoYphere which contained 2% by volume of hydrogen. The starting mixture contains all etements in the stoichiometrically required quantities, recept for fluor which is used with an excess of 30 mole~. The product ob f tained satisfies the formula BaO gEuo 1Mg3Al2Si201o~2 of barium fluorophlogopite. The emission band at 254 nm excitation has a maximum at 375 nm and a peak height of 155%-EX~MPLE 4 ~:
, A mixture is made of 35.5 g BaC03 14.6 g MgO
~, 15-85 g Mg~2 ¦ 22.4 g Al23 ;I 25.7 g S~02 3 ~.52 g Eu203.
'~
9_ 10829~0 8 4-l976 ., .
~his mixture, which contains, in addition to the stoichio-metric quantities, an excess of 20 mol% of fluorine, 5 mole %
of Si and 10 mole% of Al, is heated once for 2 hours at 1150C in a nitrogen-hydrogen mixture which contains 2% by volume of hydrogen. The material obtained has the same formula and the same emission band as the material of Example 3, the peak height being 152%, however.
A mixture is made of 106.6 g BaCO3 ~3.6 g MgO
47.5 g MgF2 73-4 g A12O3 73.5 g SiO2 10.6 g EU23 r Above the stoichiometrically required quantities, this mixture contains an excess of 20 mole % of fluorine and 20 mole% of Al. The mixture is heated for 2 hours at 1150C in air. Sub-:.
sequently the product obtained is subjected to heating for 2 hours at 1150C in a nitrogen-hydrogen mixture which con-` tains 2% by volume of hydrogen. The luminescent material prepared in this manner has the same formula as the material of Example 3 and has an emission band with maximum located . .~
at 385 nm and a peak height of 153%.
, 25 EXAMPLE 6 -~ A mixture of ,, .
. .
r~ 003 ~-4-1 976 108Z~10 .
, 15.8~ g BaCO3 3.52 g EU23 24.2 g MgO
27.6 g AlF3.3II20 36.8 g SiO2 . i i8 heated once for 2 hours at 1150C in a nitrogen-hydrogen mixtur0 which contains 8~ by volume of hydrogen. The;lumines-cent material obtained is a barium fluorophlogopite which is defective in barium and i9 defined by the formula BaO 4Euo 1 Mg3AlSi301oF2. The peak height of the emission band (maximum ~t 375 nm) i~ 110%.
.
.
.' ' " .,-. ..'' . .
~, ''`I
'i .
'~
., . ~
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A luminescent screen provided with a luminescent silicate, activated by bivalent europium, characterized in that the silicate is a fluorophlogopite of at least one of the elements potassium, strontium and barium, wherein the europium replaces part of at least one of these elements and wherein the silicate satisfies the formula K1-x-pMex-qEup+qMg3Al1+x+pSi3-x-pO10F2, in which Me represents at least one of the elements Sr and Ba, in which up to 25 mole% of the silicon may be replaced by germanium and in which 0 ? x ? 1 0.01 ? p+q ? 0.25 0 ? p ? 0.25 0 ? q ? 0.25
2. A luminescent screen as claimed in Claim 1, characterized in that 0.05 ? p+q ? 0.15.
3. A luminescent screen as claimed in Claim 1 or 2, characterized in that x = 1.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL7504440 | 1975-04-15 | ||
| NL7504440A NL7504440A (en) | 1975-04-15 | 1975-04-15 | LUMINESCENT SCREEN. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1082910A true CA1082910A (en) | 1980-08-05 |
Family
ID=19823578
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA249,872A Expired CA1082910A (en) | 1975-04-15 | 1976-04-08 | Luminescent screen |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS5927786B2 (en) |
| BE (1) | BE840702A (en) |
| CA (1) | CA1082910A (en) |
| DE (1) | DE2614255C2 (en) |
| FR (1) | FR2307863A1 (en) |
| GB (1) | GB1537330A (en) |
| NL (1) | NL7504440A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5597511A (en) * | 1992-12-31 | 1997-01-28 | Osram Sylvania Inc. | Phosphor and method of making same |
| US5306441A (en) * | 1992-12-31 | 1994-04-26 | Gte Products Corporation | Method of preparing fluoroplogopite phosphor |
| US5616285A (en) * | 1992-12-31 | 1997-04-01 | Osram Sylvania Inc. | Phosphor and method of making same |
| US5567351A (en) * | 1992-12-31 | 1996-10-22 | Osram Sylvania Inc. | Phosphor and method of making same |
| US5567352A (en) * | 1992-12-31 | 1996-10-22 | Osram Sylvania Inc. | Phosphor and method of making same |
| US5531926A (en) * | 1992-12-31 | 1996-07-02 | Osram Sylvania Inc. | Phosphor and method of making same |
| US5531928A (en) * | 1992-12-31 | 1996-07-02 | Osram Sylvania Inc. | Phosphor and method of making same |
| TWI432555B (en) * | 2011-08-12 | 2014-04-01 | Unity Opto Technology Co Ltd | Aluminate phosphor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE789747A (en) * | 1971-10-07 | 1973-04-05 | Philips Nv | LUMINESCENT SCREEN |
-
1975
- 1975-04-15 NL NL7504440A patent/NL7504440A/en unknown
-
1976
- 1976-04-02 DE DE2614255A patent/DE2614255C2/en not_active Expired
- 1976-04-08 CA CA249,872A patent/CA1082910A/en not_active Expired
- 1976-04-12 JP JP51040419A patent/JPS5927786B2/en not_active Expired
- 1976-04-12 GB GB14769/76A patent/GB1537330A/en not_active Expired
- 1976-04-13 BE BE166120A patent/BE840702A/en unknown
- 1976-04-14 FR FR7611010A patent/FR2307863A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS51124684A (en) | 1976-10-30 |
| FR2307863B1 (en) | 1980-03-21 |
| NL7504440A (en) | 1976-10-19 |
| GB1537330A (en) | 1978-12-29 |
| DE2614255A1 (en) | 1976-10-28 |
| BE840702A (en) | 1976-10-13 |
| FR2307863A1 (en) | 1976-11-12 |
| JPS5927786B2 (en) | 1984-07-07 |
| DE2614255C2 (en) | 1984-12-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4215289A (en) | Luminescent material, luminescent screen provided with such a material and low-pressure mercury vapor discharge lamp provided with such a screen | |
| US4319161A (en) | Luminescent screen and low pressure mercury vapor discharge lamp containing the same | |
| EP0094132A1 (en) | Luminescent screen | |
| CA1038619A (en) | Luminescent screen | |
| CA1082910A (en) | Luminescent screen | |
| US4524300A (en) | Luminescent screen and lamp containing the same | |
| EP0286180B1 (en) | Method of preparing a luminescent eu2+ activated strontium aluminate, aluminate obtained by said method and low-pressure mercury vapour discharge lamp provided with such an aliminate | |
| EP0082570B1 (en) | Luminescent screen | |
| CA1137295A (en) | Luminescent bivalent europium-activated barium borophosphate | |
| US4716335A (en) | Luminescent screen and low-pressure mercury vapor discharge lamp provided with such a screen | |
| JPS59102979A (en) | Fluorescent material | |
| JP3826210B2 (en) | Rare earth complex oxide phosphor | |
| GB2047262A (en) | Mluminescent materials | |
| US3502592A (en) | Calcium and strontium beta-alumina-phosphors activated by terbium and europium | |
| HU182915B (en) | Luminescent screen and method for producing the luminescent ternary aluminate usable for the screen | |
| US3718600A (en) | Method of manufacturing a luminescent silicate activated by bivalent europium | |
| JPS5944335B2 (en) | fluorescent material | |
| JPS59128211A (en) | Phosphor | |
| US4049992A (en) | Beryllium-containing europium activated phosphate phosphor, luminescent screen and discharge lamp containing same | |
| JPS5940176B2 (en) | fluorescent material | |
| CA1061102A (en) | Luminescent screen | |
| US4757233A (en) | Efficient UV-emitting phosphors based on cerium-activated calcium pyrophosphate and lamps containing the same | |
| JP4219518B2 (en) | Europium-activated composite oxide phosphor | |
| US3956663A (en) | Luminescent screen with thallium activated aluminate | |
| US4127498A (en) | Luminescent material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |