RESUMEN
We have investigated the magnetic properties of a polycrystalline sample of NdOs2Al10using neutron diffraction and inelastic neutron scattering, magnetic susceptibility and heat capacity measurements. The magnetic susceptibility data reveal an antiferromagnetic transition atTN1= 2.2 K while the heat capacity data which extend to lower temperatures show a further transition atTN2= 1.1 K. The INS measurements detect four well-resolved crystal field excitations at 7.4, 12.4, 17.6 meV and 19.2 meV at 5 K. The positions and intensities of the observed CEF excitations and the temperature dependence of previously published single crystal susceptibility data are analysed based on the orthorhombic CEF model of theJ= 9/2 ground state multiplet of Nd3+ion. The neutron diffraction study reveals the magnetic structure atT= 1.6 K to be of sine wave type (κ= [0, 0.723, 0]) with an ordered state moment ofµNd3+= 1.59(1)µBaligned along thea-axis in agreement with the single ion crystal field anisotropy. This indicates that the magnetism of NdOs2Al10is governed by the RKKY interactions in agreement with otherRT2Al10(R= Nd, Sm, Tb,T= Fe, Ru and Os), but different to that ofR= Ce based compounds where anisotropic two ions interaction as well as Kondo interaction govern the anomalous direction of the ordered state moment.
Asunto(s)
Adenosina Trifosfatasas/sangre , Anticuerpos Antinucleares/sangre , Proteínas de Unión al ADN/sangre , Dermatomiositis/inmunología , Adulto , Anciano , Brazo/diagnóstico por imagen , Estudios de Cohortes , Dermatomiositis/diagnóstico por imagen , Dermatomiositis/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Estudios Retrospectivos , Adulto JovenAsunto(s)
Paniculitis/patología , Fiebre Reumática/diagnóstico , Enfermedad Aguda , Biopsia , Proteína C-Reactiva/análisis , Diagnóstico Diferencial , Humanos , Masculino , Persona de Mediana Edad , Paniculitis/etiología , Recurrencia , Fiebre Reumática/complicaciones , Infecciones Estreptocócicas/complicaciones , Streptococcus pyogenesAsunto(s)
Acrodermatitis/inmunología , Dermis/patología , Inmunoglobulina G/inmunología , Psoriasis/inmunología , Acrodermatitis/sangre , Acrodermatitis/patología , Anciano de 80 o más Años , Biopsia , Dermis/citología , Dermis/inmunología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/metabolismo , Linfocitos/inmunología , Linfocitos/metabolismo , Masculino , Células Plasmáticas/metabolismo , Células Plasmáticas/microbiología , Psoriasis/sangre , Psoriasis/patologíaRESUMEN
We have been working on developing a low-cost tabletop NMR system. We reported that a field homogeneity as high as 50â¯ppm was achieved with a simple NMR magnet by employing two facing ferrite magnets with iron disks in between (Chonlathep et al., 2017). In this paper, we report two improvements added to our previous system: (1) an FPGA based signal processing unit to improve the S/N ratio and (2) a simple shimming mechanism to improve the field homogeneity. We obtained as high as 1â¯ppm field homogeneity in the best case. The signals from hydrogen nuclear spins in a methyl and carboxy group in acetic acid were resolved in NMR spectra.