Electronic structure of La0.65Pb0.35MnO3 perovskite studied by X-ray photoemission spectroscopy

Kowałczyk, A.; Szajek, A.; Ślebarski, A.; Baszyński, J.; Winiarski, A.

doi:10.1016/s0304-8853(00)00233-x

Cited by 11 publications

(15 citation statements)

References 15 publications

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“…The valence band (VB) spectrum of sample has a typical feature of two peaks, similar to that of LaMnO 3 doped on La-site. The corresponding value of two peaks is about 2.8 and 5.3 eV, respectively, near to 3 and 6 eV reported by Chainani et al [21] and Kowalczyk et al [22] , indicating that the Mn 3d orbit and the O 2p orbit in LaMn 1−x Te x O 3+δ are hybridized extensively into Mn 3d -O 2p bonding states and nonbonding states. Hybridized orbits play a key role in the DE interaction.…”

Section: Resultssupporting

confidence: 67%

Anomalous magnetotransport in LaMn1−x Te x O3

Tan

Chen

Zhang

2009

Sci. China Ser. G-Phys. Mech. Astron.

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The LaMn 1−x Te x O 3+δ (x=0.1, 0.2, 0.3) were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te 4+ , and Mn 3+ ions are partly converted into Mn 2+ and Mn 4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn 2+ , Mn 3+ and Mn 4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn 3+ is much larger or less than the sum of Mn 2+ and Mn 4+ ; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn 3+ is close to the sum of Mn 2+ and Mn 4+ . These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.colossal magnetoresistance, La-Te-Mn-O, magnetotransport Doped LaMnO 3 have been widely studied due to a rich variety of physical properties [1][2][3][4] . The prominent one is the colossal magnetoresistance (CMR) effect, a phenomenon of the resistive transition induced by the magnetic transition, and CMR is traditionally explained by the double exchange (DE) [5] interaction. The key role in DE mechanism is played by Mn ions, the unique magnetic ions in LaMnO 3 , which affect not only the transport behaviors of manganites by the network of Mn-OMn, but also the magnetism of materials by the spin variation of Mn ions.As demonstrated by numerous studies, the valence of Mn ions in the manganites varies with the dopant, which is considered the intrinsic factor to understanding CMR effect. Mn ions are usually all trivalent (Mn 3+ ) in LaMnO 3 .When La ions were substituted partially by divalent ions, such as Ca 2+ , Sr 2+ etc., some Mn 3+ would convert into Mn 4+ , and Mn 3+ -Mn 4+ mixed valences are formed in the stable manganites of La 1−x A x MnO 3 [5][6][7][8] .When La ions were substituted partially by tetravalent ions, such as Ce 4+ , Te 4+ ... etc., some Mn 3+ would convert into Mn 2+ , which leads to the Mn 2+ -Mn 3+ mixed valence in La 1−x A x MnO 3 (A=Ce 4+ , Te 4+ ...) [8,9] . The interactions between Mn 4+ (or Mn 2+ ) ions and the neighboring Mn 3+ ions via O 2− are believed to contribute to the DE effect.The influence of the La-site substitution in manganites on DE mechanism is indirect, depending on the conversion of Mn 3+ ions. The direct influence, undoubtedly, is the Mn-site substitution. Recently, most studies on the Mn-site substitution focus on the La 1−x A x MnO 3 or LaMnO 3 . It is found that the manganites with the formula of La 1−x A x Mn 1−y O 3 (A=Ca 2+ , Sr 2+ ...; M=Zr 2+ , Cr 3+ , Ta 4+ ,...) or LaMn 1−x B x O 3 (B=T 4+ , Mo 6+ ...) still remain Mn 3+ -Mn 4+ (or Mn 3+ -Mn 2+ ) mixed-valence, and undergo ferro-to para-magnetism (FM-PM) transition. However, both have the different magnetotransport behavior.

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Section: Resultssupporting

confidence: 67%

Anomalous magnetotransport in LaMn1−x Te x O3

Tan

Chen

Zhang

2009

Sci. China Ser. G-Phys. Mech. Astron.

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“…Similar conclusion was made in the paper [8] for La 1−x Ca x MnO 3 system exploiting the local spin-density approximation with the general potential linearized augmented plane--wave [9]. Also in the paper [10] the theoretical calculations for the La 0.75 Pb 0.25 MnO 3 were presented. In our work we have focused our attention on theoretical electronic band structure for La 2/3 Pb 1/3 MnO 3 in P 3c1 * corresponding author; e-mail: tokarz@agh.edu.pl crystal structure as a perspective application to the same compounds but substituted with Fe and their comparison with the electron photoemission spectrum and magnetic moments.…”

Section: Introductionsupporting

confidence: 77%

“…1 show some signicant dierence between two spin orientations just below the Fermi level (E F ). Whilst the spin up bands are continuous through E F the spin down have a 1.85 eV gap below the E F in comparison to 0.67 eV in the paper [10].Both band structures have a complex composition within the range from −8.2 to −1.8 eV. This complexity is better visible in DOS plots presented in Fig.…”

Section: Results and Their Analysismentioning

confidence: 73%

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

et al. 2012

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We present the theoretical study of electronic and magnetic properties in a manganese perovskite La 2/3 Pb 1/3 MnO3. The calculations were carried out in frame of the rst-principles density functional theory with the general gradient approximation using the WIEN 2K package. The P 3c1 crystal structure was taken from the detailed X-ray diraction data for the perovskite. The exact exchange energy was utilized for Mn d electrons. Density of states was determined by the modied 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 (dxz, dyz) states have twice larger contribution than (d x 2 −y 2 , dxy). We attribute this to MnO6 octahedral tilting. From the same reason d 3z 2 −r 2 state has no contribution to the density of states at the Fermi energy (EF). 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 µB, the measured one 3.48 µB/f.u.

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“…In this work we have focused our effort on the study of the effect caused by the substitution of Mn by Fe ions on photoemission from electronic states in La 0.67 Pb 0.33 Mn 1−x Fe x O 3 compounds with x = 0, 0.01, 0.03, 0.06, 0.10 and 0.15. We found only two papers on photoemission spectroscopy of La 0.67 Pb 0.33 MnO 3 [2,3] and no papers with the iron substitution. Some controversies and an inconsistent interpretation of the data still exist, especially as far as the role of Pb in valence band and the mixed valence of Mn ions are concerned.…”

Section: Substitution Of Pbmentioning

confidence: 85%

Electronic States of Collosal Magnetoresistive Manganites La_0.67Pb_0.33Mn_1-xFe_xO₃from Photoemission Spectroscopy

2010

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The electron photoemission spectra of valence bands and core-level states of manganese perovskite La0.67Pb0.33(Mn1−xFex)O3 with x = 0, 0.01, 0.03, 0.06, 0.10 and 0.15 were measured by the X-ray and Ultraviolet Photoemission Spectroscopy (XPS and UPS) below and above the metal-insulator transition. From analysis of the Mn 2p core-level spectra the ratio Mn 3+ /Mn 4+ was calculated as a function of the iron content. Comparison of the valence band spectrum with band structure calculations and with the high-resolution spectra measured at synchrotron radiation for Ca-, Ba-and Ce-substituted manganites revealed the strong hybridisation of Mn 3d and of O 2p states between −3 eV and −7 eV, and no estimated oxygen states between 0 eV and −2 eV where the Mn-3d states play a predominant role. The composition dependent insulating energy gaps were measured at room temperature. Reasons for the behaviour were discussed taking into account previous analysis of XPS/UPS spectra of other manganese perovskites.

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Electronic structure of La0.65Pb0.35MnO3 perovskite studied by X-ray photoemission spectroscopy

Cited by 11 publications

References 15 publications

Anomalous magnetotransport in LaMn1−x Te x O3

Anomalous magnetotransport in LaMn1−x Te x O3

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

Electronic States of Collosal Magnetoresistive Manganites La_0.67Pb_0.33Mn_1-xFe_xO₃from Photoemission Spectroscopy

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Electronic structure of La0.65Pb0.35MnO3 perovskite studied by X-ray photoemission spectroscopy

Cited by 11 publications

References 15 publications

Anomalous magnetotransport in LaMn1−x Te x O3

Anomalous magnetotransport in LaMn1−x Te x O3

Electronic Band Structure and Photoemission States of La2/3Pb1/3MnO3

Electronic States of Collosal Magnetoresistive Manganites La0.67Pb0.33Mn1-xFexO3from Photoemission Spectroscopy

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

Electronic States of Collosal Magnetoresistive Manganites La_0.67Pb_0.33Mn_1-xFe_xO₃from Photoemission Spectroscopy