The local structure around hydrogen atoms, phosphate ions and carbonate ions in nano crystalline nonstoichiometric hydroxy-carbonate apatite was investigated in this study. The use of 13C enriched precursors allowed to perform 1D and 2D CP MAS HETCOR (HETeronuclear CORrelation) experiments with 13C as a target spin. 2D triple resonance experiments involving the 1H/13C/31P spins were also performed. All these experiments led to the partial editing of the corresponding projection spectra and revealed fine structural details for the corresponding material. At least four 13C peaks, corresponding to carbonate ions in A sites (OH-) and B-sites (PO4 3-) were evidenced.

To better understand the effects of magnetic nanoparticles to nuclear spectra and spin relaxation in different systems, we have studied 1H NMR spectra and spin dynamics of the host system in liquid and solid suspensions of γ-Fe2O3 nanoparticles. Significant line broadening of 1H NMR spectra and growing relaxation rates were observed with increased concentration of nanoparticles in the liquid systems, with the relation T1/T2 depending on the particular host. Solid systems demonstrate inhomogeneous broadening of the spectra and practically no dependence of T1 upon the nanoparticle concentration. We explain the experimental results taking into account predomination of diffusion as a source of the relaxation, and estimate effective parameters of relaxation in the systems in study.

A novel, fast, and quiet method of magnetic resonance imaging (MRI), called SWIFT (sweep imaging with Fourier transformation) has recently been introduced. In addition to SWIFT's potential for in-vivo MRI, it creates new opportunities for MRI of materials. SWIFT currently operates in 3d radial acquisition mode. A series of segmented hyperbolic secant excitation pulses is accompanied by acquisition in the gaps. Each excitation, after correlation with the pulse results in a free induction decay (FID). The spectrum corresponding to the FID is a projection. There is very little “dead time” between excitation and acquisition, making SWIFT useful for imaging of short T2 materials, but in total imaging times comparable to fast gradient echo sequences.