Si complexes in calcium phosphate biomaterials

Gillespie, P.; Gang Wu; Sayer, M.; Stott, M. J.
January 2010
Journal of Materials Science: Materials in Medicine;Jan2010, Vol. 21 Issue 1, p99
Academic Journal
Silicon complexes in silicon doped calcium phosphate bioceramics have been studied using 29Si magic angle spinning nuclear magnetic resonance spectroscopy with the objective of identifying the charge compensation mechanisms of silicon dopants. Three different materials have been studied: a multiphase material composed predominantly of a silicon stabilized α-tricalcium phosphate (α-TCP) phase plus a hydroxyapatite (HA) phase, a single phase Si-HA material and a single phase silicon stabilized α-TCP material. NMR results showed that in all three materials the silicon dopants formed Q1 structures in which two silicate tetrahedra share an oxygen, creating an oxygen vacancy which compensated the substitution of two silicon for phosphorus. This finding may explain the phase evolution previously found where silicon stabilized α-TCP is found at low temperature after sintering.


Related Articles

  • Phase transformation of calcium phosphates in the presence of glutamic acid. Tsai, Tim W. T.; Chen, Wei-Ya; Tseng, Yao-Hung; Chan, Jerry C. C. // Canadian Journal of Chemistry;Jul2011, Vol. 89 Issue 7, p885 

    This work describes a phase-transformation pathway of calcium phosphate in the presence of glutamic acid. The route follows the order starting from amorphous calcium phosphate and brushite, then octacalcium phosphate (OCP), and finally hydroxyapatite (HAp). The preferred growth direction of the...

  • A Solid-State NMR Study of Selenium Substitution into Nanocrystalline Hydroxyapatite. Kolmas, Joanna; Kuras, Marzena; Oledzka, Ewa; Sobczak, Marcin // International Journal of Molecular Sciences;2015, Vol. 16 Issue 5, p11452 

    The substitution of selenium oxyanions in the hydroxyapatite structure was examined using multinuclear solid-state resonance spectroscopy (ssNMR). The study was supported by powder X-ray diffractometry (PXRD) and wavelength dispersion X-ray fluorescence (WD-XRF). Samples of pure hydroxyapatite...

  • Measurement of valley splitting in high-symmetry Si/SiGe quantum dots. Borselli, M. G.; Ross, R. S.; Kiselev, A. A.; Croke, E. T.; Holabird, K. S.; Deelman, P. W.; Warren, L. D.; Alvarado-Rodriguez, I.; Milosavljevic, I.; Ku, F. C.; Wong, W. S.; Schmitz, A. E.; Sokolich, M.; Gyure, M. F.; Hunter, A. T. // Applied Physics Letters;3/21/2011, Vol. 98 Issue 12, p123118 

    We have demonstrated few-electron quantum dots in Si/SiGe and InGaAs, with occupation number controllable from N=0. These display a high degree of spatial symmetry and identifiable shell structure. Magnetospectroscopy measurements show that two Si-based devices possess a singlet N=2 ground state...

  • Exact translational properties of magnetic field expansions: Application to NMR. Hennessy, Michael; Zou, Hung Bin // Review of Scientific Instruments;May90, Vol. 61 Issue 5, p1548 

    In many instances it is required to specify the magnetic field coefficients at various points away from the origin. Spherical harmonic expansions which are typically used to define the magnetic field are complex when undergoing spatial translation. A simpler approach is to use Cartesian...

  • Spin Coherence Time T2 in Metallic P-doped Si at Very Low Temperature. M. Jeong; M. Song; T. Ueno; T. Mizusaki; A. Matsubara; S. Lee // Journal of Low Temperature Physics;Feb2010, Vol. 158 Issue 3/4, p659 

    Abstract  We report NMR measurements of transverse relaxation rate 1/T 2 of the 31P nuclear spins in metallic Si:P (concentration of dopant P, n=18×1018 and 56×1018 cm−3) at temperatures between 45 mK and 5 K in a magnetic field...

  • Spin dependent recombination based magnetic resonance spectroscopy of bismuth donor spins in silicon at low magnetic fields. Mortemousque, P. A.; Sekiguchi, T.; Culan, C.; Vlasenko, M. P.; Elliman, R. G.; Vlasenko, L. S.; Itoh, K. M. // Applied Physics Letters;8/20/2012, Vol. 101 Issue 8, p082409 

    Low-field (6-110 mT) magnetic resonance of bismuth (Bi) donors in silicon has been observed by monitoring the change in photoconductivity induced by spin dependent recombination. The spectra at various resonance frequencies show signal intensity distributions drastically different from that...

  • NMR Spectroscopy of Adsorbed 129Xe at Low Temperatures and High Magnetic Fields. J. O’Neill; E. Krjukov; J. Owers-Bradley; Y. Xia // Journal of Low Temperature Physics;Mar2007, Vol. 146 Issue 5/6, p563 

    In this paper we report measurements of the nuclear magnetic resonance (NMR) spectrum of129Xe adsorbed on silica gel and Grafoil?substrates in a 15 tesla magnetic field and temperatures in the range 10?mK to 1?K. Liquid3He is used to shorten the spin lattice relaxation time of the129Xe spins and...

  • Proton CSI without solvent suppression with strongly reduced field gradient related sideband artifacts. Chadzynski, Grzegorz; Klose, Uwe // MAGMA: Magnetic Resonance Materials in Physics, Biology & Medici;Apr2013, Vol. 26 Issue 2, p183 

    Object: Non-water-suppressed MRSI (magnetic resonance spectroscopy imaging) offers a number of advantages; however, spectra are hampered by the sideband artifacts. The origin of those is associated with the vibration of the gradient coils, and most of the sidebands are assumed to be related to...

  • Numerical simulation of magnetic susceptibility effects in nuclear magnetic resonance spectroscopy. Mayer, Christian; Terheiden, Annegret // Journal of Chemical Physics;2/8/2003, Vol. 118 Issue 6, p2775 

    A numerical algorithm is proposed which is suitable to calculate the magnetic field distribution as well as the corresponding nuclear magnetic resonance time signals and frequency spectra induced by susceptibility effects. It accounts for a wide variety of system parameters such as various...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics