Perovskite-type　dense　ceramics　(La0.9Bi0.1)　AlO3　(LBAO)　have　been　prepared　through　a　solid-state　reaction　route.　LaAlO3　is　indeed　a　paraelectric,　whereas　a　significant　ferroelectric　relaxor　behavior　is　obtained　in　LBAO.　The　variations　of　ferroelectric　hysteresis　loops　versus　the　applied　field　or　frequency　indicate　the　nature　of　the　ferroelectric　domain　switching.　A　broad　dielectric　anomaly　coupled　with　the　shift　in　dielectric　maxima　toward　a　higher　temperature　with　increasing　frequency　has　been　observed　in　LBAO,　and　the　indicator　of　degree　of　diffuseness　gamma　is　about　1.86.　Moreover,　the　dielectric　relaxation,　which　follows　the　Vogel-Fulcher　relationship　with　T-VF　=　706.9　K,　f(0)　=　1.85　x　10(9)　Hz,　and　E-a　=　0.09　eV,　further　supports　spin-glass-like　characteristics.　Compared　with　LaAlO3,　the　abnormal　contraction　of　crystal　cell　is　observed　in　LBAO,　which　does　not　follow　the　normal　Vegard＇s　law.　This　can　be　attributed　to　the　covalent　hybridization　of　the　Bi3+　ions　with　the　surrounding　O2-　ions.　The　large　local　displacements　at　the　off-centered　Bi　position　lead　to　the　formation　of　polarized　nanoclusters　in　the　paraelectric　matrix　and　the　reorientation　of　these　unstable　polarized　nanoclusters　further　results　in　ferroelectric　relaxor　behavior.　(C)　2011　American　Institute　of　Physics.　[doi:　10.1063/1.3660777]