JH Schneibel, CJ Rawn, TR Watkins, and EA Payzant Metals and Ceramics Division, Oak Ridge Nationa... more JH Schneibel, CJ Rawn, TR Watkins, and EA Payzant Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831. ... 11 CJ Rawn, JH Schneibel, CM Hoffmann, and CR Hubbard, Intermetallics 9, 209 2001 . ...
Single crystals and powder samples of Ba4ZnTi11O27 and Ba2ZnTi5O13 have been synthesized and stud... more Single crystals and powder samples of Ba4ZnTi11O27 and Ba2ZnTi5O13 have been synthesized and studied using single-crystal X-ray precession photographs and X-ray powder diffraction. Unit cell dimensions were calculated from a least-squares refinement with a final maximum Δ2θ of 0.05°. Both phases were found to have monoclinic cells, space group C2/m. The refined lattice parameters for the Ba4ZnTi11O27 compound are a= 19.8687(8) Å, b=11.4674(5) Å, c=9.9184(4) Å, β= 109.223(4)°, and Z=4. The refined lattice parameters for the Ba2ZnTi5O13 compound are a= 15.2822(7) Å, b=3.8977(1) Å, c=9.1398(3) Å, β=98.769(4)°, and Z=2.
ABSTRACT Our previous research demonstrated that biosynthesized magnetite (biomagnetite) exhibite... more ABSTRACT Our previous research demonstrated that biosynthesized magnetite (biomagnetite) exhibited similar properties as chemically synthesized magnetite. To complement uses of the traditional chemically synthesized magnetite (chem-magnetite) biomagnetite must be exhibit highly reproducible sizes and be available in scalable qualities. Here we emphasize potentially advantageous properties of biomagnetite regarding size, reproducibility and scaling availability. Average crystallite size (ACS) of biomagnetites ranging from 10-100 nm was determined after varied 1) incubation times, 2) substitution of metal and lanthanide species, 3) degrees of congruent incorporation or retardation of substitution elements, 4) bacterial species with their varied ability to substitute elemental species, and 6) incubation temperature that can influence coalescence. The microbial production of biomagnetite has demonstrated capacity to make highly crystalline nanoscale particles of metal-substituted ferrites including compounds of Co, Ni, Cr, Mn, Zn and the rare earths in large quantity. Selected Zn-substituted magnetite (nominal composition of Zn0.6Fe2.4O4) has been recovered at over 1 kg (wet weight) in batches from 30 L fermentations. The massively produced extracellular magnetites were confirmed to exhibit good mono- dispersity via transmission electron microscopy (TEM). TEM also validated highly reproducible ACS of 13.1±0.8 nm size as determined through X-ray diffraction (N=7) at a 99 % confidence level. Based on the scale-up experiments performed using the 35 L reactor, the reduction in ACS variability and shorted incubation times of several days may be attributed to increases of electron donor input, and availability of divalent ions of the substitution metal with less ferrous ions in the case of doped magnetite, or a combination of the above. While costs of commercial nanometer sized magnetite (25-50 nm) may vary from 500/kg to > 1,000/kg, microbial mass production is likely capable of producing 13-90 nm magnetite or doped magnetites at a fraction of the cost of traditional chemical synthesis. While there are numerous approaches for the synthesis of nanoparticles, bacterial fermentation of magnetite or metal-substituted magnetite may represent a disruptive manufacturing technology with respect to yield, reproducibility and scalability.
... During this session, Kevin Rhodes, a graduate student from the University of Tennessee, was r... more ... During this session, Kevin Rhodes, a graduate student from the University of Tennessee, was recognized as the Power Diffraction SIG's 2011 ... analysis Wednesday morning the M/N/P SIGs co-sponsored with the Canadian Division a tribute session honoring Lachlan Cranswick. ...
... GA MILLER Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 8040... more ... GA MILLER Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 80401, USA EA PAYZANT, CJ RAWN Metals and Ceramics Division, Oak Ridge National Laboratory §, Oak Ridge, Tennessee 37831, USA ...
... CY Jones,* SL Marshall, BC Chakoumakos, CJ Rawn, and Y. Ishii . Oak Ridge National L... more ... CY Jones,* SL Marshall, BC Chakoumakos, CJ Rawn, and Y. Ishii . Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, and Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun 311-1195, Japan. J. Phys. Chem. ...
JH Schneibel, CJ Rawn, TR Watkins, and EA Payzant Metals and Ceramics Division, Oak Ridge Nationa... more JH Schneibel, CJ Rawn, TR Watkins, and EA Payzant Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831. ... 11 CJ Rawn, JH Schneibel, CM Hoffmann, and CR Hubbard, Intermetallics 9, 209 2001 . ...
Single crystals and powder samples of Ba4ZnTi11O27 and Ba2ZnTi5O13 have been synthesized and stud... more Single crystals and powder samples of Ba4ZnTi11O27 and Ba2ZnTi5O13 have been synthesized and studied using single-crystal X-ray precession photographs and X-ray powder diffraction. Unit cell dimensions were calculated from a least-squares refinement with a final maximum Δ2θ of 0.05°. Both phases were found to have monoclinic cells, space group C2/m. The refined lattice parameters for the Ba4ZnTi11O27 compound are a= 19.8687(8) Å, b=11.4674(5) Å, c=9.9184(4) Å, β= 109.223(4)°, and Z=4. The refined lattice parameters for the Ba2ZnTi5O13 compound are a= 15.2822(7) Å, b=3.8977(1) Å, c=9.1398(3) Å, β=98.769(4)°, and Z=2.
ABSTRACT Our previous research demonstrated that biosynthesized magnetite (biomagnetite) exhibite... more ABSTRACT Our previous research demonstrated that biosynthesized magnetite (biomagnetite) exhibited similar properties as chemically synthesized magnetite. To complement uses of the traditional chemically synthesized magnetite (chem-magnetite) biomagnetite must be exhibit highly reproducible sizes and be available in scalable qualities. Here we emphasize potentially advantageous properties of biomagnetite regarding size, reproducibility and scaling availability. Average crystallite size (ACS) of biomagnetites ranging from 10-100 nm was determined after varied 1) incubation times, 2) substitution of metal and lanthanide species, 3) degrees of congruent incorporation or retardation of substitution elements, 4) bacterial species with their varied ability to substitute elemental species, and 6) incubation temperature that can influence coalescence. The microbial production of biomagnetite has demonstrated capacity to make highly crystalline nanoscale particles of metal-substituted ferrites including compounds of Co, Ni, Cr, Mn, Zn and the rare earths in large quantity. Selected Zn-substituted magnetite (nominal composition of Zn0.6Fe2.4O4) has been recovered at over 1 kg (wet weight) in batches from 30 L fermentations. The massively produced extracellular magnetites were confirmed to exhibit good mono- dispersity via transmission electron microscopy (TEM). TEM also validated highly reproducible ACS of 13.1±0.8 nm size as determined through X-ray diffraction (N=7) at a 99 % confidence level. Based on the scale-up experiments performed using the 35 L reactor, the reduction in ACS variability and shorted incubation times of several days may be attributed to increases of electron donor input, and availability of divalent ions of the substitution metal with less ferrous ions in the case of doped magnetite, or a combination of the above. While costs of commercial nanometer sized magnetite (25-50 nm) may vary from 500/kg to > 1,000/kg, microbial mass production is likely capable of producing 13-90 nm magnetite or doped magnetites at a fraction of the cost of traditional chemical synthesis. While there are numerous approaches for the synthesis of nanoparticles, bacterial fermentation of magnetite or metal-substituted magnetite may represent a disruptive manufacturing technology with respect to yield, reproducibility and scalability.
... During this session, Kevin Rhodes, a graduate student from the University of Tennessee, was r... more ... During this session, Kevin Rhodes, a graduate student from the University of Tennessee, was recognized as the Power Diffraction SIG's 2011 ... analysis Wednesday morning the M/N/P SIGs co-sponsored with the Canadian Division a tribute session honoring Lachlan Cranswick. ...
... GA MILLER Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 8040... more ... GA MILLER Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 80401, USA EA PAYZANT, CJ RAWN Metals and Ceramics Division, Oak Ridge National Laboratory §, Oak Ridge, Tennessee 37831, USA ...
... CY Jones,* SL Marshall, BC Chakoumakos, CJ Rawn, and Y. Ishii . Oak Ridge National L... more ... CY Jones,* SL Marshall, BC Chakoumakos, CJ Rawn, and Y. Ishii . Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, and Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun 311-1195, Japan. J. Phys. Chem. ...
Uploads
Papers