9Be knight shift in the normal state of UBe13

9Be NMR spectra have been studied in the heavy-fermion compound UBe13 as functions of spectrometer frequency, crystal orientation, and temperature. BeI-site isotropic Knight shift and BeII-site anisotropic shifts, corresponding hyperfine fields, and quadrupolar tensors have been determined. For T {less-than or approximate} 10 K a typical heavy-fermion Knight shift anomaly is observed. © 1987

Franchetti, Fortunata; verehel. Walzel

(1801 - 1876), Sängeri

Cubic three-dimensional hybrid silica solids for nuclear hyperpolarization

Mathieu Baudin is kindly acknowledged for his contribution to dissolution DNP experiments.International audienceHyperpolarization of metabolites by dissolution dynamic nuclear polarization (D-DNP) for MRI applications often requires fast and efficient removal of the radicals (polarizing agents). Ordered mesoporous SBA-15 silica materials containing homogeneously dispersed radicals, referred to as HYperPolarizing SOlids (HYPSOs), enable high polarization – P(1H) = 50% at 1.2 K – and straightforward separation of the polarizing HYPSO material from the hyperpolarized solution by filtration. However, the one-dimensional tubular pores of SBA-15 type materials are not ideal for nuclear spin diffusion, which may limit efficient polarization. Here, we develop a generation of hyperpolarizing solids based on a SBA-16 structure with a network of pores interconnected in three dimensions, which allows a significant increase of polarization, i.e. P(1H) = 63% at 1.2 K. This result illustrates how one can improve materials by combining a control of the incorporation of radicals with a better design of the porous network structures