University of Puerto Rico-Cayey
Department of Biology / RISE Program
BIOL 3955 Seminar Investigation: Biomedical Techniques Spring 2015
Final Reportx
Written Report Assessment Criteria May _____ 2015
Students’ Names _16. Anibal Tornés_and 1. Abneil Alicea
Research Solid State Synthesis of Mixed Metal Oxides
Evaluator’s Name Dr. Eneida Díaz and Dr. Elena González Total Points /75
Content Poor Fair Average Good Excellent
Introduction
1. Adequately presents the theme 1 2 3 4 5
2. Summarizes related studies well as part of the background information
1 2 3 4 5
3. Includes adequate CSE citations in the text/Cited Literature 1 2 3 4 5
4. Hypothesis and/or problem well formulated 1 2 3 4 5
5. Indicates significance of the study 1 2 3 4 5
Experimental Design and Methodology
6. Describes effectively the lab strategy and/or methods 1 2 3 4 5
7. Presents only the necessary steps to understand the strategy 1 2 3 4 5
Results
8. Presents results adequate for data collected 1 2 3 4 5
9. Visual aids enhance comprehension of results 1 2 3 4 5
Discussion of results
10. Includes whether or not the hypothesis(es) was proven and or research question(s) answered
1 2 3 4 5
11. Refers to implications for the future 1 2 3 4 5
Language and report organization Poor Fair Average Good Excellent
12. Uses correct grammar, syntax, punctuation, spelling 1 2 3 4 5
13. Demonstrates clarity 1 2 3 4 5
14. Demonstrates coherence with appropriate connectors 1 2 3 4 5
15. Body of report well organized 1 2 3 4 5
Solid State Synthesis of Mixed Metal Oxides
Anibal Tornésa,1 & Abneil D. Aliceab,2
a University of Puerto Rico at Cayey, RISE Program, Department of General Sciences
b University of Puerto Rico at Cayey, RISE Program, Department of Chemistry
A B S T R A C TThe search for a perpetual energy source has been the goal of every material chemist. Mixing and matching elements to obtain new compounds is the base of every innovative application in the chemistry field. The importance of our research goes beyond obtaining crystals, it consists of characterizing plausible compounds which might have superconductivity characteristics and other applicable properties. The problem that we are facing is to determine if certain elements might provide useful structures to apply in the technologically dependent world we live in and suffice the energy crisis that surrounds us. Our hypothesis states that even though oxygen is present, after heat application, oxide crystals will form and their characterization will provide magnetism, optical, and even electronic properties. After reacting ternary compounds in a high temperature furnace and analyzing them in a microscope we managed to obtain compact structures which merely provided oxide powders with crystal structures. This finding of oxide powder alludes to our hypothesis and demonstrated that it was partially proved, because the oxide powder has a crystal structure, yet it does not have enough potential to be characterized for all the properties we stated.
1. Introduction
Solid-state synthesis is a branch of material chemistry which consists of mixing and matching solids in
order to obtain new compounds which could have unique properties useful for the technologically dependent world
we live in. During our investigation we principally worked with metals in their solid powdered form and
synthesized what are known as mixed-metal oxide, these are metal compounds with intrinsic oxygen within them.
When superconductors such as high purity silicon were implemented in the industrialization process, this ¨eternal
energy source¨ gained the scientific community's acceptance. In recent years, electrochemical capacitors, also
known as supercapacitors, have received a large amount of attention as an important power storage device due to
their high power density, fast recharge capability and long cycle life (Chen et al. 2015).
If we take a moment to think about the amount of possible compounds the periodic table holds, we will
surely be wasting our time since the possibilities are infinite. This is why the research had to follow an extremely
strict protocol since we dealt with a numerous amount of highly reactive metals, as a precaution and minimization
of the elements the maximum weight we had of reactives is 30 mg. This environmentally favorable protocol will
help decrease the ecological footprint we might have when disposing of the different compounds formed. When
reactants are mixed in carbon coated silica tubes and put into a GSL-1100x high temperature vacuum tube furnace
at temperatures over (1,000 °C), one of the powder state solids liquefies first and mixes with its adjacent solid,
forming compounds (Cotton et al. 1995).
We expect that after this reactions occur, a series of analysis will be run to determine if our synthesis can
provided crystal structures products. Also by observing the product color make inferences about what it might or
might not be its oxide states. If the investigation provide positive results it could continued into the characterization
step, which would let us determine the specific properties of the compound and would let us determined if it might
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provide magnetism, optical, and even electronic properties which could help derive the next-generation of
“superconductors”.
2. Materials & Methods
2.1 Reactant Selection
Our research began with a comprehensive study of the reactant selection. After doing a broad analysis of
our elements peculiar oxidation states, fusion points, and the minimum amount of milligrams they might need to
react as shown in (Fig 1.1), we determined to work with ternary and quaternary compounds. These two divisions,
principally from groups 13-15 on the periodic table aided us to determine how intrinsic oxygen reacts in them.
Chosen elements for reactions
Ternary Quaternary
1 In : 1 Sb 1 S : 1 Bi : 1 In
1 In : 1 Bi 1 Pb : 1 Sn : 1 S
2 In : 1 Sn 2 In : 1 Sn : 1S
2 In : 1 Pb 2 In : 1 Sn : 2 S
(Fig 1.1)
2.2 Silica tube preparation
The elements we used will be inserted into different silica tubes, passed under heat alignment and carbon
coating protocols. The original tube was 4 feet long and split into 4 halves of 12 inches each with a crystal cutter so
they would fit in the fume hood. This split was done using an oxygen acetylene torch which provided a blue flame
usually used for welding. This split and tube alignment was done in order to then put our reactions in, but first we
carbon coated each 6 inch tube. Carbon coating is a process which will help inhibit light from reacting with our
compounds and the same compounds from reacting with the tube.
2.3 Stoichiometric Weight Conversion
In order to decrease the ecological footprint we mentioned at the beginning of this paper, we had a limit of
30 mg from the heaviest weighting element in the ratio. According to the mass and ratio of each element in the
compound, the 30 mg limit will establish the weight of the other elements in the reaction, except for oxygen as
shown in (Fig 1.2). This step requires mathematical stoichiometric conversion efficiency, considering ratios and
precise molar masses since the weighing could give place to a significant percent of human error, and in
consequence the reaction might not take place effectively.
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Ternary Milligram (mg) reason Quaternary Milligram (mg) reason
1 In : 1 Sb 30 mg Sb + 28 mg In 1 S : 1 Bi : 1 In 5mg + 30mg + 20mg
1 In : 1 Bi 30 mg Bi + 16 mg In 1 Pb : 1 Sn : 1 S 30mg + 20mg + 5mg
2 In : 1 Sn 30 mg In + 16 mg Sn 2 In : 1 Sn : 1S 30mg + 16mg + 4mg
2 In : 1 Pb 30 mg In + 27 mg Pb 2 In : 1 Sn : 2 S 30mg + 16mg + 8mg
(Fig 1.2)
2.4 GSL-1100x application
The fusion points of the
elements we put together to form
compounds go over (1,000 °C), which
is why we used a special GSL-1100x
high temperature vacuum tube furnace.
Depending on the reactions we deposit
in, the calibration will vary since not
every compound similar fusion points.
The heat is distributed during a period
of about one week max in the order of
heating and cooling to provide a space
for crystal formation. Figure 1.3,
obtained from the MTI operation
manual portrays a general overview of
the calibration and adaptable heat the
furnace may go through.
(Fig 1.3) MTI Operation Manual
3. Results and Discussion
The reaction were taken from the furnace and used dissecting microscope techniques to observe compact
structures, before considering that they were crystals we went on to attempt and break them. With the use of the
microscope and tweezers we decomposed the structures and confirmed that it was just compacted powder.
According to tabulated powder results and their oxidation numbers, we determined that each structure complied to
its peculiar color. Indium appears in all the ternary reactions, nevertheless we may observe how the elements
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different oxidation numbers may be determined by color. Due to the reaction between low melting mixed metal
oxides there is a transference of electrons which are represented by their oxidation numbers as shown in (Fig 1.4).
Ternary Reaction Results
Solid Products Element Oxidation Number
1 In: 1 Sb
1 Sb +3
2 In : 1 Sn
1 Sn +2
1 In : 1 Bi
1 Bi +3
2 In : 1 Pb
1 Pb +2
(Fig 1.4)
The way the heat is distributed is diagrammed in (Fig 1.5) shown below, in the the first few days the temperature
increase 10 degrees per minute until it reaches the target temperature. This target temperature is based on the
melting points of the different reactants inside the tubes. Once the furnace reaches this target temperature it remain
at this temperature for two days. When the two day counting concludes, the furnace temperature decreases 5
degrees per minute until it reaches the room temperature again. This way the metals can react in a better way with
each other when liquified. After the room temperature has been reached we may go on to observe the products
achieved in each one of our silica tubes.
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(Fig 1.5)
From a chemical perspective of what was occurring in the furnace we might conclude the following, crystal
formation consist of two basic steps; homogenization and a maximum melting point accompanied by a constant
cooling curve. Out of the four compounds we worked with, only one of them turned out to react as loose oxide
powder, whilst the other three compacted themselves.. Permitting an even more constant temperature will permit a
better structure homogenization and a paulatine slope decrease might even provide more space for a stable crystal
structure formation.
Our hypothesis was partially proved, we were not able to find any type of crystals from the ternary
reactions shown in Figure 1.4, yet the visible structures we observed are just homogenized powder. Future work
will have to take into consideration a more constant calibration curve and a more comprehensive analysis of proper
compounds to mix, we suggest the use of bioinformatics to decrease this trial and error percent. Taking into
consideration work done by (Koscielski et al.2012) we may confirm that for future studies, the use of radioactive
compounds would be more efficient than dealing with oxides. Yet radioactive compounds produce high quantities
of energy, but have not proven to be sustainable enough for the planet. Hence dealing with these metal compounds,
would leave a less significant ecological footprint and would therefore provide clean energy; an appropriate
suggestion would be to include oxygen isolation chambers since their crystal product might show to be more pure.
Cited Literature:
Chen S, Xue M, Li Y, Zhu L, Zhang D, Fang Q, Qiu S. 2015. Porous ZnCo2O4 nanoparticles derived from a new mixed-metal organic framework for supercapacitors. Royal Society of Chemistry (RSC) (2) . [2014 Oct 17, cited 2015 April 29] 2:177-183. DOI: 10.1039/c4qi00167b
Cotton FA, Wilkinson G, Gaus PL. 1995. Basic Inorganic Chemistry. 3rd edition. New York. John Wiley & Sons, Inc.
Koscielski L, Ringe E, Van Duyne R, Ellis D, Ibers J. 2012. Single-Crystal Structures, Optical Absorptions, and Electronic Distributions of Thorium Oxychalcogenides ThOQ (Q=S,
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