The internal friction (loss tangent) of solids is normally measured, as a function of temperature, with a torsion pendulum operating in free decay. Curves of the internal friction and the oscillation frequency, against temperature, are obtained at various moments of inertia, to extract the parameters characteristic of the relaxation process (relaxation time and strength). In all these experiments only the temperature is considered as an independent variable and the moment of inertia of the pendulum is mainly used to shift the internal friction peaks in the temperature scale. It is pointed out in the paper that the moment of inertia is also an independent variable which can be used to determine, with high accuracy, if the measured peak is of the Debye type or not. A new torsion pendulum, with continuously variable moment of inertia is presented, which allows measurements of the partial derivative of the internal friction and the oscillation frequency with respect to the moment of inertia, at constant temperature. Finally, some measurements of the Snoek relaxation in Nb-O alloys are presented, to show the applicability of the concepts developed in the paper. © 1992 Società Italiana di Fisica.
Documento: | Artículo |
Título: | Influence of the moment of inertia of the pendulum on the internal friction (loss tangent) measured by free decay |
Autor: | Povolo, F.; Molinas, B.J.; Lambri, O. |
Filiación: | Departemento de Materiales, Comisión Nacional de Energía Atómica, Av. del Libertador 8250, Buenos Aires, 1429, Argentina Facultad de Ciencias Exactas y Naturales Departemento de Física, Universidad de Buenos Aires, Pabellón 1, Ciudad Universitaria, Buenos Aires, 1428, Argentina Instituto de Física Rosario (CONICET-UNR), Av. Pellegrini 250, Rosario, 2000, Argentina Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, La Plata, Argentina |
Palabras clave: | Anelasticity, internal friction, and mechanical resonances |
Año: | 1992 |
Volumen: | 14 |
Número: | 3 |
Página de inicio: | 279 |
Página de fin: | 286 |
DOI: | http://dx.doi.org/10.1007/BF02457390 |
Título revista: | Il Nuovo Cimento D |
Título revista abreviado: | Il Nuovo Cimento D |
ISSN: | 03926737 |
CODEN: | HGHPF |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03926737_v14_n3_p279_Povolo |