  The crystal and magnetic structures of AlFe2B2 have been studied with a
combination of X-ray and neutron diffraction and electronic structure
calculations. The magnetic and magnetocaloric properties have been investigated
by magnetisation measurements. The samples have been produced using high
temperature synthesis and subsequent heat treatments. The compound crystallises
in the orthorhombic crystal system Cmmm and it orders ferromagnetically at 285
K through a second order phase transition. At temperatures below the magnetic
transition the magnetic moments align along the crystallographic $a$-axis. The
magnetic entropy change from 0 to 800 kA/m was found to be -1.3 J/K kg at the
magnetic transition temperature.
