Surface electronic and magnetic properties ofLa2/3Sr1/3MnO3<

Abstract

The surface electronic and magnetic properties of epitaxial La 2/3 Sr 1/3 MnO 3 / SrTiO 3 ͑001͒ films with extended bulk metallicity above the Curie temperature have been investigated. By angle-resolved photoemission we show that the surface electronic structure presents the e g dispersing band, responsible for the halfmetallicity, crossing the Fermi level and leading to a sharp Fermi edge. Quasiparticle excitations, reflecting the coherent polaronic ferromagnetic and metallic ground state, are clearly visible at the Fermi level and 16 K, while they disappear at room temperature, where a Fermi edge is still clearly visible. X-ray magnetic circular dichroism shows a robust subsurface magnetization up to T C , while spin-polarization Mott spectroscopy indicates a rapid suppression of the surface magnetization which disappears around room temperature. These results clearly demonstrate that a robust surface metallic electronic structure does not necessarily ensure the concomitant stabilization of long-range magnetic order.

Measuring magnetic profiles at manganite surfaces with monolayer resolution

“…1(a) taken at 7º, showing a higher inversion angle and therefore a thinner "dead layer" in their capped film, as verified by the fit magnetization profiles. In [12] there is no discussion of the fitting parameters used to simulate the data, but the results clearly demonstrate the high quality of the heterostructures investigated, and that capped surfaces appear to be qualitatively different than free surfaces, as has been commented recently [18].…”

Ferromagnetism in epitaxial orthorhombic YMnO3 thin films

“…3. It is well known that in manganites the energy splitting DE 3s between the high-spin and the low-spin final state configuration is roughly proportional to the Mn formal valence, with a decrease of roughly 0.7 eV per unitary decrease in valence [23][24][25]. Data in Fig.…”

Valence state of manganese and iron ions in La1−A MnO3 (A = Ca, Sr) and Bi1−Sr FeO systems from Mn2p, Mn3s, Fe2p and Fe3s X-ray photoelectron spectra. Effect of delocalization on Fe3s spectra splitting

“…Separate representatives of the systems Bi 1-x Sr x FeO 3 and La 1-x A x MnO 3 (A=Ca,Sr), as well as the whole systems formed by step-by-step variation of one of the elements (Sr) have been studied in detail starting from the sixties of last century [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. An interest to the Bi 1-x Sr x FeO 3 system is caused by a wide spectrum of its electrical and magnetic properties, and by the variation of electrical resistivity under magnetic field [6].…”