  The Be/X-ray binary system A0535+262 underwent a giant outburst in May-June
2005, followed by a dimmer outburst in August-September 2005. This increased
intensity provided an opportunity to search for redshifted neutron-capture
lines from the surface of the neutron star. If discovered, such lines would
constrain the neutron star equation of state, providing the motivation of this
search. The spectrometer (SPI) on board the INTEGRAL satellite observed the
dimmer outburst and provided the data for this research. We have not detected a
line with enough significance, with the width-dependent upper limits on the
broadened and redshifted neutron capture line in the range of (2 - 11) x
10^(-4) photons cm^(-2) s^(-1). To our knowledge, these are the strongest upper
limits on the redshifted 2.2 MeV emission from an accreting neutron star. Our
analysis of the transparency of the neutron star surface for 2.2 MeV photons
shows that photons have a small but finite chance of leaving the atmosphere
unscattered, which diminishes the possibility of detection.
