"Kengo Oka,Koichiro Nabetani,Chika Sakaguchi,Hayato Seki,Michel  Czapski,Yuichi Shimakawa,Masaki Azuma","Tuning negative thermal expansion in Bi<sub>1</sub>-<sub>X</sub>Ln<sub>X</sub>NiO<sub>3</sub>(Ln=La,Nd,Eu,Dy)",,"APPLIED PHYSICS LETTERS",,"Vol. 103",,"pp. 061909-1-3",2013,Aug.