J. Phys. IV France
Volume 125, June 2005
Page(s) 505 - 508

J. Phys. IV France 125 (2005) 505-508

DOI: 10.1051/jp4:2005125117

Investigation of the size-effect in cobalt-ferrite nanoparticles using photoacoustic spectroscopy

P.C. Morais1, A.C. Oliveira1, A.L. Tronconi1, R.L. Santos2 and E.C.D. Lima2

1  Universidade de Brasília, Instituto de Física, Núcleo de Física Aplicada, 70919-970, Brasília, DF, Brazil
2  Universidade Federal de Goiás, Instituto de Química, 74001-970, Goiânia, GO, Brazil

In this study the photoacoustic signal of cobalt-ferrite based particles has been investigated near the semiconductor band-edge and in the very small-size limit. In these limits we find that the photoacoustic signal scales with both the zero- and the three-dimensional density of states. In addition, we find that the relative contribution to the photoacoustic signal, due to the zero-dimension-like nanoparticles, decreases linearly with the increasing average nanoparticle size. From this linear behavior we estimate the electron-hole pair size in cobalt-ferrite nanoparticles around 1.6 nm

© EDP Sciences 2005