"Kengo Oka,Masaichiro Mizumaki,Chika Sakaguchi,Alexandra  Sinclair,Clemens  Ritter,J. Paul Attfield,Masaki Azuma","Intermetallic charge-transfer transition in Bi<sub>1</sub>�|<sub>x</sub>La<sub>x</sub>NiO<sub>3</sub> as the origin of the colossal negative thermal expansion",,"PHYSICAL REVIEW B",,"Vol. 88",,,2013,July