Accession Number : AD0019236


Title :   On the Nuclear Magnetic Resonance in Metals and Alloys


Corporate Author : HARVARD UNIV CAMBRIDGE MA CRUFT LAB


Personal Author(s) : Bloembergen, N ; Rowland, T J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/019236.pdf


Report Date : 20 Aug 1953


Pagination or Media Count : 48


Abstract : A Pound-Knight-Watkins type of RF spectrometer (Rev. Sci. Instr. 21:219, 1950) was used in measuring the shift of nuclear resonance and the line width in alpha- and beta-Sn, Th, Pb, and several alloys. A permanent magnet with a field of about 6000 gauss in a 1.25-in. gap and with 4-in.-diam pole faces was also used. A few measurements were made with an electromagnet at fields between 2000 and 5500 gauss. The samples were made from powdered metals suspended in mineral oil. Gray Sn showed no shift relative to the resonance in insulating compounds, but white Sn had an anisotropic shift of 0.79% along the tetragonal axis and 0.74% perpendicular to it. A theory is given for the anisotropy and asymmetry of the observed line. Thallium had an anomalously broad resonance line with a shift of 1.54%. The shift in Th alloys varied continuously with composition in each phase and had discontinuities when phase transitions occurred. The intensity of the Cu resonance in pure Cu was increased by annealing and decreased by cold work. The intensity in alloys such as alpha- brass and Cu-Ag decreased rapidly with increasing Zn or Ag content. These effects are explained in terms of quadrupole interaction.


Descriptors :   *METALS , *NUCLEAR MAGNETIC RESONANCE , PHASE TRANSFORMATIONS , POWDERS , INSULATION , QUADRUPOLE MOMENT , ALLOYS , ASYMMETRY , ANISOTROPY , SHIFTING , RESONANCE , WIDTH , MINERAL OILS , RADIOFREQUENCY , PERMANENT MAGNETS , SPECTROMETERS , ELECTROMAGNETS , THALLIUM , INTERACTIONS , COLD WORKING , ANNEALING


Subject Categories : Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE