SOLID-STATE SYNTHESIS AND CHARACTERIZATION OF LOW-MELTING MIXED-METAL OXIDES University of Puerto Rico at Cayey Department of Chemistry QUIM4999 Gerardo P. Ramos Otero Principal Investigator: Dr. Lukasz Koscielski Abstract A variety of inorganic compounds have useful features because of their physical properties. Properties such as magnetism, resistivity, thermopower, conductivity, and optical band gaps demand the constant attention of the scientific community; developing novel compounds. The principal purpose in the research project is to synthesize new ternary compounds focusing on the low-melting mixed- metal oxides with general formula M x M’ y O z . The compounds are synthesized via solid-state methods, this involves the synthesis of compounds at high temperatures using as a starting materials powders, granules, or crystals. The elements tin, lead, arsenic, bismuth, antimony, tellurium are the low-melting metals used to synthesize the oxides. Powder and single-crystal X-ray diffraction is used to characterize the structures of the synthesized oxides. The determination of physical properties among the low-melting mixed-metal oxides is unique to each compound.
Transcript
SOLID-STATE SYNTHESIS AND CHARACTERIZATION OF LOW-MELTING
MIXED-METAL OXIDES
University of Puerto Rico at CayeyDepartment of Chemistry
QUIM4999
Gerardo P. Ramos OteroPrincipal Investigator: Dr. Lukasz Koscielski
Abstract
A variety of inorganic compounds have useful features because of their physical properties. Properties such as magnetism, resistivity, thermopower, conductivity, and optical band gaps demand the constant attention of the scientific community; developing novel compounds. The principal purpose in the research project is to synthesize new ternary compounds focusing on the low-melting mixed-metal oxides with general formula MxM’yOz. The compounds are synthesized via solid-state methods, this involves the synthesis of compounds at high temperatures using as a starting materials powders, granules, or crystals. The elements tin, lead, arsenic, bismuth, antimony, tellurium are the low-melting metals used to synthesize the oxides. Powder and single-crystal X-ray diffraction is used to characterize the structures of the synthesized oxides. The determination of physical properties among the low-melting mixed-metal oxides is unique to each compound.
Introduction
A significant amount of inorganic compounds have shown exceptional properties which makes them target of research. Inorganic compounds like indium-tin oxide, are known for their transparent conducting properties, merging two magnificent properties, electrical conductivity and optical transparency which have great application in solar-cell technologies. Other interesting and useful properties like superconductivity, magnetic susceptibilities, resistivity, and thermopower are present in inorganic compounds. There is a lot to explore in this field, a lot of exciting inorganic compounds not yet been created.
Solid-state chemistry is the study of the design, modeling, synthesis, fabrication, processing, spectroscopy characterization, physical properties determination of solid-phase materials.
The first phase in the research is the creation of new compounds via solid-state synthesis. Solid-state synthesis is characterize for the use of high temperature profiles ranging from a few hundred to a few thousand degrees Celsius. The starting materials are solids consisting of powders, granules or crystals, the products are also in a solid-phase. The high temperature profile is the key for the reaction to occur and it involves three simple steps; first the heat provides the energy needed for bond disruption in the starting materials, then a rearrangement occur, and finally the reformation of bonds upon the cooling step. Once products are formed the second phase in the research begins, this phase is the characterization of the new synthesized oxide structurally via single-crystal X-ray diffraction. Finally the third phase consist of the physical properties characterization, that will reveal the possible applications.
An oxide is a compound with at least one oxygen atom in its chemical formula. A low-melting mixed-metal oxide is one with one or more poor metals and an oxygen atom. The metals that are mostly associated with the low-melting mixed-metal oxides consist of gallium (Ga), germanium (Ge), arsenic (As), indium (In), tin (Sn), antimony (Sb), tellurium (Te), tallium (Tl), lead (Pb), and bismuth (Bi).
Solid-state Chemistry
Synthesis of Solid-Phase
Materials
Characterization of Solid-Phase
Materials
Physical Characterization of Solid-Phase
Materials
Synthesis
Characterization
Physical Properties
Determination
Methodology
Synthesis
Vessel
Preparation
•Silica tubes of 48 inches are going to be cut into 4 tubes of 12 inches.
•Each tube of 12 inches will be cut with an acetylene-oxygen flame providing two tubes with flame-sealed ends.
•Finally the tubes will be carbon coated by adding several drops of acetone to the tube and placing the tube in a flame to decompose the acetone into water and carbon that will form a thin film inside the tube.
Loading of Reagents
•The reagents will be load into the tubes in milligram quantities.
•The heaviest reactant is assigned with an amount of ~20mg, the quantities of the additional reactants will be calculated based on this.
• If a reagent is air and moisture-sensitive, then the loading process will be under an inert-atmosphere inside a glove-box.
Heating of Reactions
•The loaded tubes will be placed in a computer-controlled furnace and heated according to specific temperatures profile.
•There are 3 steps:•Heating Step•The reagent with the lower melting point will melt and serve as a medium for the reaction to occur.
•Plateau Step •The temperature is constant.
•Slow-cooling Step•This step allows the crystal formation.
Diagram 1. Synthesis Procedure
Synthesis
Characterization
Physical Properties
Determination
Methodology
Characterization
Physical Properties Determination
The physical characterization will depend solely on the product under study, and the measurements will be considered case-by-case.
Product analyze by EDX (Electron
Dispersive X-Ray Spectroscopy)
Powder
Powder X-ray Difraction
Novel Compound
Reload into silica tube with a
crystallizing agent
Crystal
Single-crystal X-ray Difraction
Solve Structure
Previously Synthesized
Crystal
Single-crystal X-ray Difraction
Solve Structure
Diagram 2. Characterization Procedure
Experimental Section
The first step in the research is the analysis of literature related to the synthesis of low-melting mixed-metal oxides (the Table A-1 of the annex summarize all the information found in the literature). The Table1 presents the ternary low-melting mixed-metal oxides already created. As the Table 1 demonstrate there is a lot to work with in the synthesis of oxides with low-melting metals. The Table 2 shows relevant information about the reagents used in the synthesis.
Table 1. Already synthesized ternary oxides
Table 2. Information of the reagents used in for the synthesis
Experimental Section
In the following reactions the target ternary oxides will form from the reaction between two metals; the oxygen atom comes from the atmosphere. The reactions between the group 14 of the periodic table are present in the Table 3, the reagents used are tin (Sn) and lead (Pb). The reactions between the groups 14 and 15 of the periodic table are present in the Table 4, 5, and 6; the reagents used are tin (Sn), arsenic (As), antimony (Sb), and bismuth (Bi). The synthesis procedure can be seen in the Diagram 1. An example of the quantity calculation is demonstrated in the Equation 1.
Group 14/14
Group 14/15
Table 6. Loaded reactions using metals from groups 14 and 15 of the periodic table.
Table 5. Loaded reactions using metals from groups 14 and 15 of the periodic table.
Table 4. Loaded reactions using metals from groups 14 and 15 of the periodic table.
Table 3. Loaded reactions using metals from group 14 of the periodic table.
Equation 1. Example of the quantity calculation for the reaction 2.
Future Work
Method 1[21]
Method 2[2]
The synthesis of new ternary oxides will continue using two different methodologies. The first methodology involves the reaction between an oxide and a metal resulting in a ternary oxide. The second methodology involves the reaction between two different binary oxides providing a ternary oxide. The reaction designs for the Method 1[21] are present in the Table 7 and for the Method 2[2] in the Table 8. The resulting oxides will be then characterize structurally via powder and single-crystal X-ray diffraction. The physical properties determination will be measure individually, and includes magnetic susceptibilities, conductivity, resistivity, and thermopower.
M + M’2O3 + CH3CO2H (80%), saturated with NH4C2H3O2 at 500K for 10d
M2O3 + M’O2 at 1000oC for 2-3h
Table 7. Reaction designs for method 1.
Table 8. Reaction designs for method 2.
References
[1] Grabmaier, B. C.; Haussühl, S.; Klüfers, P. Crystal growth, structure, and physical properties of Bi2Ge3O9. Zeitschrift für Kristallographic. 1979. 149, 261-267.
[2] Aurivillius, B.; Lindblom, C.; Sténson P. The crystal structure of Bi2GeO5. Acta chem. Scand. 1964. 6, 1555-1557.
[3] Jones, R. H.; Knight, K. S. The structure of γ-Bi2Sn2O7 at 725oC by high-resolution neutron diffraction: implications for bismuth(III)-containing pyrochlores. J Chem. Soc.. 1997. 2551-2555.
[4] Samalat, A.; Hector, A. L.; McMillan, P. F.; Ritter C. Structure, Bonding, and Phase Relations in Bi2Sn2O7 and Bi2Ti2O7 Pyrochlores: New Insights from High Pressure and High Temperature Studies. Inorg. Chem. 2011. 50, 11905-11913.
[5] Wang, H.; Wang, B.; Wang, R.; Li, Q. Ab initio study of structural and electronic properties of BiAlO3 . Physica B. 2007. 390, 96-100.
[6] Belik, A.; Wuernisha, T.; Kamiyama, T.; Mori, K.; Maie, M.; Nagai, T.; Matsui, Yoshio.; Takayama-Murumachi, E. High-Pressure Synthesis, Crystal Structures, and Properties of Perovskite-like BiAlO3 and Pyroxene-like BiGaO3. Chem. Mater. 2006. 18, 133-139.
[7] Belik, A; Stefanivich, S.; Lazoryak, B.; Takayama-Muromachi, E. BiInO3: A Polar Oxide with GdFeO3-Type Perovskite Structure. Chem. Mater. 2006. 18, 1964-1968.
[8] Kaczkowski, J.; Jezierski, A. Electronic Structure of the Cubic Perovskites BiMO3 (M = Al, Ga, In, Sc). Acta Physica Plonica A. 2013. 124, 852-854.
[9] Edwards, D. D.; Mason, T. O. A new transparent conducting oxide in the Ga2O3-In2O3-SnO2 system. Appl. Phys. Lett.. 1997. 70, 1706-1708.
[10] Kahn, A.; Agafonov, V.; Michel, D.; Perez, M. New Gallium Germanates with Tunnel Structures: α-Ga4GeO8 and Ga4Ge3O12. Journal of solid state chemistry. 1986. 65, 377-382.
[11] Túnez, F.M.; Andrade-Gamboa, J.; González, J.A.; Esquivel, M.R. A new polymorph of GaAsO4. Materials letters. 2012. 79, 202-204.
[12] Santamaria, D.; Haines, J.; Amador, U.; Moran, E.; Vegas, A. Structural characterization of a new high-pressure phase of GaAsO4. Acta Crystallographica. 2006. B62, 1019-1024.
[13] Arroyo, E.; Moran, E. A Comparative Study of GaAsO4 Polymorphs: ab initio Calculations on High-pressure Forms. Z. Naturforsch. 2008. 63b, 668-672.
[14] Philippot, E.; Armand, P.; Yot, P.; Cambon, O.; Goiffon, A.; McIntyre, G.J.; Bordet, P. Neutron and X-Ray Structure Refinements between 15 and 1073K of Piezoelectric Gallium Arsenate, GaAsO4: Temperature and Pressure Behavior Compared with Other α-Quartz Materials. Journal of Solid State Chemistry. 1999. 146, 114-123.
References
[15] Labéguerie, P.; Harb, M.; Baraille, I.; Rérat, M. Structural, electronic, elastic, and piezoelectric properties of α-quartz and MXO4 (M= Al, Ga, Fe; X= P, As) isomorph compounds: ADFT study. Physical Review. 2010. B81, 1098-1026.
[16] Donaldson, J.D.; Kjekshus, A.; Nicholson, D.G.; Rakke, T. Properties of Sb-compounds with Rutile-like Structures. Acta chemica scandinavica. 1975. A 29, 803-809.
[17] Fu, Y.; Xue, H.; Qin, M.; Liu, P.; Fu, X.; Li, Z. Nanocrystalline GaSbO4 with high surface area prepared via a facile hydrothermal method and its photocatalytic activity study. Journal of Alloys and Compounds. 2012. 522, 144-148.
[18] Gonzalez, G.B.; Okasinski, J.S.; Mason, T.O.; Buslaps, T.; Honkimaki, V. In situ studies on the kinetics of formation and crystal structure of In4Sn3O12 using high-energy x-ray diffraction. Journal of Applied Physics. 2008. 104.
[19] Nadaud, N.; Nanot, M.; Jové, J.; Roisnel, T. A structural study of tin doped indium oxide (ITO) ceramics using 119Sn Mossbauer spectroscopy and neutron diffraction. Engineering Materials. 1997. 132-136, 1373-1376.
[20] Araki, T.; Moore, P.B. The crystal structure of paulmooreite, Pb2[As2O5]: dimeric arsenite groups. American Mineralogist. 1980. 65, 340-345.
[22] Losilla, E.; Arande, M.; Javier, F.; Bruque, S. Crystal Structure and Spectroscopic Characterization of MAs2O6 (M = Pb, Ca). Two Simple Salts with AsO6. J. Phys. Chem. 1995. 99, 12975-12979.
[23] Marsh, R.; Bernal, I. More space-group changes. Acta Cryst. 1995. B51, 300-307.
[24] Ke, Y.; Li, J.; Zhang, Y.; Lu, S.; Lei, Z. Synthesis and structure of a 3-rings antimony germinate: Sb2Ge3O9. Solid state sciences. 2002. 4, 803-806.
[25] Touboul, M.; Feutelais, Y. Structure du Germanate de Thallium(I): Tl8Ge5O14. Acta Cryst. 1979. B35, 810-815.
