Slow fluctuationsoftheelectricalresistance R havebeensystematicallyobservedinthreeglass- ceramics containingaggregatesofmagnetitenanoparticles,inmeasurementswhere R wasstudiedasa functionoftimeatthemagneticremanence.Thesefluctuationsareshowntobeanintrinsic(i.e.,not instrumentalorspurious)featureofthesematerials.Theassociatedelectricalnoisehasbeenobtained by performinganumericalFFTtransformofdifferentsegmentsofthe R(t) curvesafterproperbaseline subtraction. Inthisway,thespectraldensityhasbeeninvestigatedintheverylow-frequencyregion (1103ofo0.2Hz),usuallynotcoveredinstandardnoisemeasurements.Thespectraldensityshows a 1/fa behaviour(with affi1.6)inallcases.Theresultsarediscussedintermsoftheexistingmodels about conductancefluctuationsinhalf-metallicoxidesinthehoppingregime.Itissuggestedthat electron trapping–detrappingmechanisms(thoughttobethesourceofelectricalnoise)playarelevant role inthehoppingprocessesbetweenadjacentnanoparticleaggregatesofmagnetite,whichdominate the material’sresistivity.
Room-temperature relaxation of the electrical resistance and electrical 1/f(alpha) noise observed at very low frequency in the remanent state of glass-ceramics containing magnetite nanoparticles / P., Allia; Coisson, Marco; Tiberto, PAOLA MARIA; Vinai, Franco; O., Bretcanu. - In: JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS. - ISSN 0304-8853. - 322:9-12(2010), pp. 1286-1289. [10.1016/j.jmmm.2009.04.074]
Room-temperature relaxation of the electrical resistance and electrical 1/f(alpha) noise observed at very low frequency in the remanent state of glass-ceramics containing magnetite nanoparticles
COISSON, MARCO;TIBERTO, PAOLA MARIA;VINAI, FRANCO;
2010
Abstract
Slow fluctuationsoftheelectricalresistance R havebeensystematicallyobservedinthreeglass- ceramics containingaggregatesofmagnetitenanoparticles,inmeasurementswhere R wasstudiedasa functionoftimeatthemagneticremanence.Thesefluctuationsareshowntobeanintrinsic(i.e.,not instrumentalorspurious)featureofthesematerials.Theassociatedelectricalnoisehasbeenobtained by performinganumericalFFTtransformofdifferentsegmentsofthe R(t) curvesafterproperbaseline subtraction. Inthisway,thespectraldensityhasbeeninvestigatedintheverylow-frequencyregion (1103ofo0.2Hz),usuallynotcoveredinstandardnoisemeasurements.Thespectraldensityshows a 1/fa behaviour(with affi1.6)inallcases.Theresultsarediscussedintermsoftheexistingmodels about conductancefluctuationsinhalf-metallicoxidesinthehoppingregime.Itissuggestedthat electron trapping–detrappingmechanisms(thoughttobethesourceofelectricalnoise)playarelevant role inthehoppingprocessesbetweenadjacentnanoparticleaggregatesofmagnetite,whichdominate the material’sresistivity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
