  We report that low frequency (up to 200 kHz) noise spectra of magnetic tunnel
junctions with areas ~10^{-10}cm^2$ at 10 Kelvin deviate significantly from the
typical 1/f behavior found in large area junctions at room temperature. In most
cases, a Lorentzian-like shape with characteristic time between 0.1 and 10 ms
is observed, which indicates only a small number of fluctuators contribute to
the measured noise. By investigating the dependence of noise on both the
magnitude and orientation of an applied magnetic field, we find that
magnetization fluctuations in both free and reference layers are the main
sources of noise in these devices. At small fields, where the noise from the
free layer is dominant, a linear relation between the measured noise and
angular magnetoresistance susceptibility can be established.
