TEM Study of Epitaxial Growth of La_0.65Pb_0.35MnO₃ on LaA1O₃ and Its Relation to Electronic Structure and Spin Polarization

Lu Yuan, Physics Department, University of Nebraska
Peter Dowben, University of Nebraska - Lincoln
Y. Liu, University of Nebraska - Lincoln
Sy-Hwang Liou, University of Nebraska-Lincoln

Document Type Article

Published in Microsc. Microanal. 8 (Suppl. 2), 2002. Copyright © Microscopy Society of America 2002. Used by permission.

Abstract

We showed that the surfaces of ferromagnets differ substantially from the bulk for three different classes of potential half-metallic ferromagnets (metallic in spin majority and insulating in spin minority) as well as an elemental local moment ferromagnet (strained gadolinium). We have been careful to correlate electronic structure, electron spin polarization and structural studies to obtain a more complete picture. We showed that the surfaces of La_xA_1-xMnO₃ (A= Ca, Sr, Ba, Pb) are dominated by a large surface enthalpy or by surface segregation [I], while CrO₂ surfaces are very unstable [2]. Indeed surface composition has a profound effect upon the measured polarization asymmetry of the unoccupied bands for the La_xA_1-xMnO₃ (M= Sr, Pb) [3]. In this study, we examine both the microstructure and epitaxial growth of La_0.65Pb_0.35MnO₃ on LaAlO₃ using transmission electron microscopy (TEM).