Summary
In order to measure the anisotropy in paramagnetic resonance absorption in single crystals, a method has been devised which does not require initial knowledge of the directions of the principal magnetic axes, and by which it is possible to determine the principal values together with the directions of the axes. It is shown that under certain assumptions the characteristic surface ofg is an ellipsoid, and that thus, with a proper choice of the axes, the following equation holds:g=g x α 2+g y β 2+ +g z γ 2, whereα, β, γ stand for the direction cosines ofH. The method has been applied for completing previous measurements, thus rendering their interpretation possible.
Riassunto
Per misurare l’anisotropia nell’assorbimento per risonanza paramagnetica nei monocristalli β stato ideato un metodo che non richiede la conoscenza preventiva delle direzioni degli assi magnetici principali e per mezzo del quale è possibile determinare i valori principali con le direzioni degli assi. Si dimostra che, ammesse determinate ipotesi, la superficie caratteristica dig è un ellissoide e che così, con un’appropriata scelta degli assi, valgono le seguenti equazioni:g=g x α 2+g y β 2+g z γ 2 doveα, β, γ sono i coseni direttori diH. Il metodo è stato applicato per il completamento di precedenti misure, rendendone così possibile l’interpretazione.
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This work forms part of a programme of research undertaken with the financial support of the Consiglio Nazionale delle Ricerche, through the Comitato per la Fisica, for which the authors wish to express their sincere gratitude.
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Palma Vittorelli, M.B., Palma, M.U., Palumbo, D. et al. Determination and properties of anisotropy in paramagnetic resonance absorption. Nuovo Cim 2, 811–819 (1955). https://doi.org/10.1007/BF02725041
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DOI: https://doi.org/10.1007/BF02725041