Compound

Abstract

A compound represented by one of the formulae:

Ba.sub.aMo.sub.bO.sub.c(1),

MO.sub.dP.sub.eO.sub.f(2) or

Ba.sub.gMo.sub.hP.sub.iO.sub.j(3) wherein for formula (1) the ratio of a:b is greater than 1:1, wherein for formula (2) the ratio of d:e is from 1:100 to 0.45:1 or from 0.55:1 to 100:1, wherein for formula (3) the ratio of g:h is from 1:7 to 1:2 and the ratio of g:i is from 1:3 to 1:1, or the ratio of g:h is from 0.6:1 to 100:1 and the ratio of g:i is from 2.2:1 to 100:1, and wherein the molybdenum present within the compound is in the 4+ oxidation state.

Claims

1. A compound represented by one of the formulae:
Ba.sub.aMo.sub.bO.sub.c(1),
MO.sub.dP.sub.eO.sub.f(2) or
Ba.sub.gMo.sub.hP.sub.iO.sub.j(3) wherein for formula (1) the ratio of a:b is greater than 1:1, wherein for formula (2) the ratio of d:e is from 1:100 to 0.45:1 or from 0.55:1 to 100:1, wherein for formula (3) the ratio of g:h is from 1:7 to 1:2 and the ratio of g:i is from 1:3 to 1:1, or the ratio of g:h is from 0.6:1 to 100:1 and the ratio of g:i is from 2.2:1 to 100:1, and wherein the molybdenum present within the compound is in the 4+ oxidation state.

2. The compound according to claim 1, wherein for formula (1) the ratio of a:b is greater than 1.05:1, but less than 100:1, preferably greater than 1.1:1, more preferably greater than 1.2:1, most preferably greater than 1.3:1, but preferably less than 50:1, more preferably less than 10:1.

3. The compound according to claim 1, wherein for formula (2) the ratio of d:e is from 1:50 to 0.4:1 or from 0.6:1 to 50:1, preferably the ratio of d:e is from 1:10 to 0.35:1 or from 0.7:1 to 10:1.

4. The compound according to claim 1, wherein for formula (3), when the ratio of g:h is from 0.6:1 to 100:1 and the ratio of g:i is from 2.2:1 to 100:1, the ratio of g:h is from 0.7:1 to 100:1, preferably from 0.8:1 to 100:1, more preferably from 0.9:1 to 100:1, even more preferably from 1:1 to 100:1.

5. The compound according to claim 1, wherein for formula (3), when the ratio of g:h is from 0.6:1 to 100:1 and the ratio of g:i is from 2.2:1 to 100:1, the ratio of g:i is from 2.5:1 to 100:1, preferably from 2.8:1 to 100:1, more preferably from 3:1 to 100:1.

6. The compound according to claim 1, wherein for formula (3) the ratio of h:i is from 0.5:1 to 4.5:1, preferably from 0.7:1 to 4.3:1, more preferably from 0.8:1 to 4.1:1, even more preferably from 0.9:1 to 4:1.

7. The compound according to claim 1, wherein for formula (1) the ratio of a:b is greater than 1.2:1, but less than 50:1, for formula (2) the ratio of d:e is from 1:10 to 0.35:1 or from 0.7:1 to 10:1, and for formula (3) the ratio of g:h is from 0.9:1 to 100:1 and the ratio of g:i is from 2.8:1 to 100:1.

8. The compound according to claim 1, wherein for formula (1), a=2 to 100, preferably a=2 to 50, more preferably a=2 to 10, even more preferably a=2 to 6 or a=3 to 6, and/or wherein for formula (1), b=1 to 100, preferably b=1 to 50, more preferably b=1 to 10, even more preferably b=1 to 5 or b=2 to 5.

9. The compound according to claim 1, wherein for formula (1), a=2 to 6, b=1 to 5 and c=3 to 20.

10. The compound according to claim 1, wherein the compound represented by formula (1) is selected from Ba.sub.2MoO.sub.4, Ba.sub.3MoO.sub.5, and Ba.sub.3Mo.sub.2O.sub.7, or a compositional equivalent of any of these compounds.

11. The compound according to claim 1, wherein for formula (2), d=2 to 6, e=2 to 8 and f=6 to 20.

12. The compound according to claim 1, wherein the compound represented by formula (2) is selected from Mo.sub.2P.sub.2O.sub.9, Mo.sub.2P.sub.6O.sub.19, Mo.sub.4P.sub.2O.sub.13 and Mo.sub.6P.sub.2O.sub.17, or a compositional equivalent of any of these compounds.

13. The compound according to claim 1, wherein for formula (3), g=2 to 100, preferably g=2 to 50, more preferably g=2 to 10, even more preferably g=2 to 6 or g=3 to 6, and/or wherein for formula (3), h=2 to 100, preferably h=2 to 50, more preferably h=2 to 10, even more preferably h=2 to 8 or h=2 to 6, and/or wherein for formula (3), i=2 to 100, preferably i=2 to 50, more preferably i=2 to 10, even more preferably i=2 to 6.

14. The compound according to claim 1, wherein for formula (3), g=2 to 6, h=2 to 8, i=2 to 10 and j=10 to 20.

15. A coated glass article comprising: a glass substrate and a coating on the glass substrate, wherein the coating comprises a first layer based on a compound represented by one of the formulae:
Ba.sub.aMo.sub.bO.sub.c(1),
MO.sub.dP.sub.eO.sub.f(2) or
Ba.sub.gMo.sub.hP.sub.iO.sub.j(3) wherein for formula (1) the ratio of a:b is greater than 1:1, wherein for formula (2) the ratio of d:e is from 1:100 to 100:1, wherein for formula (3) the ratio of g:h is from 1:100 to 100:1, wherein for formula (3) the ratio of g:i is from 1:100 to 100:1, and wherein the molybdenum present within the compound is in the 4+ oxidation state.

16. The coated glass article according to claim 15, wherein for formula (2) the ratio of d:e is from 1:50 to 50:1, preferably the ratio of d:e is from 1:10 to 10:1, and/or wherein for formula (3) the ratio of g:h is from 1:50 to 100:1, preferably from 1:10 to 100:1, more preferably from 0.9:1 to 100:1, even more preferably from 1:1 to 100:1, and/or wherein for formula (3) the ratio of g:i is from 1:10 to 100:1, preferably from 1:1 to 100:1, more preferably from 2.8:1 to 100:1, and/or wherein for formula (3) the ratio of h:i is from 1:100 to 100:1, preferably from 1:10 to 50:1, more preferably from 0.5:1 to 50:1, more preferably from 0.8:1 to 10:1, even more preferably from 0.9:1 to 5:1.

17. The coated glass article according to claim 15, wherein the coating further comprises one or more lower layer between the glass substrate and the first layer, and one or more upper layer located further from the glass substrate than the first layer.

18. A method of manufacturing the compound according to claim 1, comprising: i) for compounds represented by formula (1), providing a Ba-containing precursor, a Mo-containing precursor and an O-containing precursor, wherein at least two of said precursors may be the same precursor, and reacting said precursors to form a compound represented by formula (1), or ii) for compounds represented by formula (2), providing a Mo-containing precursor, a P-containing precursor and an O-containing precursor, wherein at least two of said precursors may be the same precursor, and reacting said precursors to form a compound represented by formula (2), or iii) for compounds represented by formula (3), providing a Ba-containing precursor, a Mo-containing precursor, a P-containing precursor and an O-containing precursor, wherein at least two of said precursors may be the same precursor, and reacting said precursors to form a compound represented by formula (3).

19. The method according to claim 18, wherein the Ba-containing precursor comprises one or more of BaO, Ba.sub.2MoO.sub.5, BaMoO.sub.4, BaCO.sub.3, Ba(thd).sub.2 (Barium tetramethylheptanedionate), Barium bis(N,N,N,N,N-pentamethyldiethylenetriamine)bis[BREW] (Ba(C.sub.9H.sub.23N.sub.3).sub.2[C.sub.xH.sub.yC(O)CHC(O)C.sub.xH.sub.y].sub.2 (x=3-4, y=2x+1)), Bis(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3, 5-octanedionate)barium [Ba(FOD).sub.2], Bis(pentamethylcyclopentadienyl)barium, and Bis(n-propyltetramethylcyclopentadienyl)barium, wherein the Mo-containing precursor comprises one or more of MoO.sub.2, Ba.sub.2MoO.sub.5, BaMoO.sub.4, MoO.sub.3, MoO.sub.2(thd).sub.2 (Molybdenum(VI) di-oxo bis(2,2,6,6-tetramethyl-3,5-heptanedionate), MoCl.sub.5, Mo(CO).sub.6, MoO.sub.2(acac).sub.2, Bis(t-butylimido)bis(dimethylamino)molybdenum(VI), Bis(ethylbenzene)molybdenum, and Cycloheptatriene molybdenum tricarbonyl, wherein the P-containing precursor comprises one or more of a trialkyl phosphate e.g. Triethylphosphate or Trimethylphosphate, P.sub.2O.sub.5, NH.sub.4H.sub.2PO.sub.4, (NH.sub.4).sub.2HPO.sub.4, H.sub.3PO.sub.4, triethylphosphite, phosphorus chloride, phosphorus oxychloride, and Tris(dimethylamino)phosphine, and wherein the O-containing precursor comprises one or more of ethyl acetate, molecular oxygen, water, dimethyamino ethanol (DMAE), Ba.sub.2MoO.sub.5, BaMoO.sub.4, BaCO.sub.3, Ba(thd).sub.2 (Barium tetramethylheptanedionate), Barium bis(N,N,N,N,N-pentamethyldiethylenetriamine)bis[BREW] (Ba(C.sub.9H.sub.23N.sub.3).sub.2[C.sub.xH.sub.yC(O)CHC(O)C.sub.xH.sub.y].sub.2 (x=3-4, y=2x+1)), 5-octanedionate)barium [Ba(FOD).sub.2], MoO.sub.3, MoO.sub.2(thd).sub.2 (Molybdenum(VI) di-oxo bis(2,2,6,6-tetramethyl-3,5-heptanedionate), Mo(CO).sub.6, MoO.sub.2(acac).sub.2, Cycloheptatriene molybdenum tricarbonyl, Triethylphosphate, Trimethylphosphate, P.sub.2O.sub.5, NH.sub.4H.sub.2PO.sub.4, H.sub.3PO.sub.4, triethylphosphite, phosphorus oxychloride, and Tris(dimethylamino)phosphine.

Description

[0111] The invention will now be further described by way of the following specific embodiments, which are given by way of illustration and not of limitation, with reference to the accompanying drawings in which:

[0112] FIG. 1 is a schematic view, in cross-section, of a coated glass article in accordance with the present invention with an at least three-layer coating, and

[0113] FIG. 2 is a perspective view of a sintered body in accordance with the present invention.

[0114] FIG. 1 shows a cross-section of a coated glass article 1 according to certain embodiments of the present invention. Coated glass article 1 comprises a transparent float glass substrate 2 that has been sequentially coated using magnetron sputtering with one or more lower layers based on dielectric material 3, a layer based on a compound according to the present invention 4, and one or more upper layers based on dielectric material 5.

[0115] FIG. 2 shows a perspective view of a sintered body 6 in accordance with the present invention which is a ceramic sputtering target comprising a compound according to the present invention.

EXAMPLES

[0116] Direct Preparation of Ba.sub.3Mo.sub.2O.sub.7 as a Thin Film by Pulsed Laser Deposition (PLD):

[0117] Preparation of Ba.sub.2MoO.sub.5 powder precursor:

2BaCO.sub.3+MoO.sub.3.fwdarw.Ba.sub.2MoO.sub.5+2CO.sub.2

[0118] BaCO.sub.3 was heated overnight at 500? C., while MoO.sub.3 was heated overnight at 200? C. 10.51 g BaCO.sub.3 and 3.83 g MoO.sub.3 were weighed out whilst hot and mixed together. The mixture was ball milled in ethanol at 350 rpm for 15 mins, followed by 10 mins rest, for 10 cycles, reversing the direction between each cycle. The powder mixture was then dried on a hot plate overnight before being heated in an alumina crucible at 1200? C. for 25 hr. The powder mixture was reground in a pestle and mortar and heated in an alumina crucible at 1200? C. for 25 hr. A pure product was confirmed by XRD.

[0119] Preparation of BaMoO.sub.4 powder precursor:

BaCO.sub.3+MoO.sub.3.fwdarw.BaMoO.sub.4+CO.sub.2

[0120] BaCO.sub.3 was heated overnight at 500? C., while MoO.sub.3 was heated overnight at 200? C. 3.98 g BaCO.sub.3 and 2.91 g MoO.sub.3 were weighed out whilst hot and mixed together. The mixture was ball milled in ethanol at 350 rpm for 15 mins, followed by 10 mins rest, for 10 cycles, reversing the direction between each cycle. The powder mixture was then dried on a hot plate overnight before being heated in an alumina crucible at 900? C. for 25 hr. A pure product was confirmed by XRD.

[0121] A sintered pellet of a composite of Ba.sub.2MoO.sub.5 (8.64 g)+BaMoO.sub.4 (5.70 g) with a Ba:Mo ratio of 3:2 was prepared. This was achieved by intimately mixing powders of these two components and then sintering via direct current sintering (1050? C., 50 MPa for 3 mins) to give a relative density of >90% (typically ?95% relative density).

[0122] PLD was then carried out by depositing onto SrTiO.sub.3 single crystals utilising the sintered pellet and the following growth conditions: 800-900? C. (preferred 850? C.), 0.3-30 mTorr 2.5% H.sub.2/Ar gas pressure (preferred 30 mTorr), 4.00 sccm flow rate, laser pulse frequency=2 Hz, 1.3-2.5 J/cm.sup.2 laser fluence (preferred 2.0 J/cm.sup.2).

[0123] A SrTiO.sub.3 protective capping layer to prevent oxidation from the atmosphere was grown at 600? C. under base pressure vacuum (5?10.sup.?7 to 5?10.sup.?8 Torr), pulse frequency=2 Hz and with a laser fluence of 1.70 J/cm.sup.2. A SrTiO.sub.3 target was used which was prepared from SrCO.sub.3 (8.05 g) and TiO.sub.2 (4.35 g) by grinding with a pestle and mortar, heating at 1000? C. for 12 hr, regrinding, pressing into a 25 mm diameter pellet and heating at 1300? C. for 12 hr.

[0124] The composition of Ba.sub.3Mo.sub.2O.sub.7 was determined from an X-ray diffraction model and energy dispersive X-ray spectrometry on a transmission electron microscopy instrument. Ba.sub.3Mo.sub.2O.sub.7 demonstrated semiconducting properties with a room temperature resistivity of 7?10.sup.?2 ohm cm.

[0125] Other examples according to the invention are prepared using three bulk powder synthesis approaches. These are undertaken using the precursors set out in Table 1 and the methods described below.

[0126] Method 1: For each compound, the appropriate precursors are mixed in the amounts shown in Table 1 to give a nominal precursor Ba.sub.gMo.sub.2/3hP.sub.iO.sub.j and heated in air at 600? C. for 10 hr to eliminate any CO.sub.2, H.sub.2O, and NH.sub.3. The precursors are then transferred to an Ar filled glovebox and mixed with ?h mol equivalent Mo.sup.0 metal further heated at 850? C. for 24 hr in an evacuated (<10.sup.?3 mTorr) quartz tube to yield the desired compound.

[0127] Method 2: For each compound the precursors are mixed by grinding in an agate pestle and mortar in the amounts shown in Table 1 while contained within an Ar filled glovebox. The mixture is pressed into a 10 mm diameter pellet in ?0.5 g batches, and placed into an alumina crucible which is subsequently sealed in an evacuated (<10.sup.?3 mTorr) quartz ampule. The ampule is heated to 1100? C. and kept at the temperature for 12 hours. Once cooled the ampule is opened in the Ar filled glovebox, reground, resealed in an evacuated quartz ampule and heated again at the reaction temperature for another 12 hours. The heating and regrinding is repeated up to four times.

[0128] Method 3: A precursor of the correct Ba:Mo ratio, as shown in Table 1, with Mo in the 6+ oxidation state is synthesised using methods reported in the literature. The Mo.sup.6+ precursor (0.5 g) is then reduced using a flow (80 mL/min) of 5% H.sub.2 in Ar at 1150? C. for up to 36 hours with intermittent grinding every 12 hours. The reduced sample is transferred to an Ar filled glovebox without exposure to air.

TABLE-US-00001 TABLE 1 Compound Prepared Method Ba precursor Mo precursor P precursor BaMo(PO.sub.4).sub.2 1 BaCO.sub.3 (0.99 g) MoO.sub.3 (0.48 g) NH.sub.4H.sub.2PO.sub.4 (1.15 g) Mo (0.16 g, after first heating) BaMo(PO.sub.4).sub.2 2 BaO (0.77 g) MoO.sub.2 (0.48 g) P.sub.2O.sub.5 (0.71 g) Mo.sub.2P.sub.2O.sub.9 2 MoO.sub.2 (1.28 g) P.sub.2O.sub.5 (0.71 g) Mo.sub.2P.sub.2O.sub.9 1 MoO.sub.3 (0.96 g) NH.sub.4H.sub.2PO.sub.4 (1.15 g) Mo (0.32 g, after first heating) Mo.sub.2P.sub.6O.sub.19 1 MoO.sub.3 (0.96 g) NH.sub.4H.sub.2PO.sub.4 (3.45 g) Mo (0.32 g, after first heating) Mo.sub.2P.sub.6O.sub.19 2 MoO.sub.2 (1.28 g) P.sub.2O.sub.5 (0.71 g) Mo.sub.4P.sub.2O.sub.13 1 MoO.sub.3 (0.96 g) NH.sub.4H.sub.2PO.sub.4 (0.58 g) Mo (0.32 g, after first heating) Mo.sub.4P.sub.2O.sub.13 2 MoO.sub.2 (1.28 g) P.sub.2O.sub.5 (0.35 g) Ba.sub.2MoO.sub.4 3 Ba.sub.2MoO.sub.5 (0.50 g) + H.sub.2 Ba.sub.2MoO.sub.4 2 BaO (0.35 g) BaMoO.sub.3 (0.65 g) Ba.sub.2MoO.sub.4 2 BaO (0.71 g) MoO.sub.2 (0.29 g) Ba.sub.3MoO.sub.5 2 BaO (0.78 g) MoO.sub.2 (0.22 g) Ba.sub.3MoO.sub.5 2 BaO (0.52 g) BaMoO.sub.3 (0.48 g) Ba.sub.3Mo.sub.2O.sub.7 2 BaO (0.21 g) BaMoO.sub.3 (0.79 g) Ba.sub.3Mo.sub.2O.sub.7 2 BaO (0.64 g) MoO.sub.2 (0.36 g)

[0129] The invention is not restricted to the details of the foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.