ACTA

Electronic Band Structure and Photoemission States of La_2/3Pb_1/3MnO₃

W. Tokarz^a, M. Kowalik^b,a, R. Zalecki^a and A. Kołodziejczyk^a
^aAGH University of Science and Technology, Department of Solid State Physics, al. A. Mickiewicza 30, 30-059 Cracow, Poland
^bDepartment of Physics, Rzeszów University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland

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We present the theoretical study of electronic and magnetic properties in a manganese perovskite La_2/3Pb_1/3MnO₃. The calculations were carried out in frame of the first-principles density functional theory with the general gradient approximation using the WIEN 2K package. The P3c1 crystal structure was taken from the detailed X-ray diffraction data for the perovskite. The exact exchange energy was utilized for Mn d electrons. Density of states was determined by the modified tetrahedron method. As a result we get a valence band for the spin up and down density of states with the gap for the latter of 1.85 eV. We noticed that conduction band is mainly dominated by d spin up manganese electrons and Mn (d_xz, d_yz) states have twice larger contribution than (d_{x² - y²}, d_xy). We attribute this to Mn-O₆ octahedral tilting. From the same reason d_{3 z² - r²} state has no contribution to the density of states at the Fermi energy (E_F). Comparison of total density of states with the ultraviolet photoemission spectroscopy measurements shows similar features especially as far as the lead spectral intensity from the 6s electrons at about - 10 eV is concerned. The calculated total magnetic moment per formula unit is 3.66 μ_B, the measured one 3.48 μ_B/f.u.

DOI: 10.12693/APhysPolA.121.1151
PACS numbers: 71.20.-b, 71.55.Ak, 72.80.Ga, 75.47.Lx, 79.60.-i