DIRECT EVIDENCE FOR ITINERANT MAGNETITE ABOVE AND BELOW THE VERWEY TRANSITION TEMPERATURE

2002 ◽  
Vol 09 (02) ◽  
pp. 907-912 ◽  
Author(s):  
Y. Q. CAI ◽  
K. NAKATSUJI ◽  
S. OHNO ◽  
T. IIMORI ◽  
M. YAMADA ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Synchrotron Radiation ◽  
Direct Evidence ◽  
Electronic States ◽  
Photoemission Spectroscopy ◽  
Partial Density ◽  
Verwey Transition ◽  
Temperature Dependent ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Minority Spin

The valence electronic states of Fe 3 O 4(111) films on Pt(111) were studied using temperature-dependent spin- and angle-resolved photoemission spectroscopy with synchrotron radiation. The majority- and minority-spin partial density of states (DOS) has been obtained at 300 K and 100 K, above and below the Verwey transition temperature (TV ~ 120 K ). The spectra still show substantial k-dependence at 100 K in the 3d region. This provides the most direct experimental evidence that the 3d electrons are itinerant even at T < TV.

scholarly journals Emergent flat band electronic structure in a VSe2/Bi2Se3 heterostructure

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Turgut Yilmaz ◽  
Xiao Tong ◽  
Zhongwei Dai ◽  
Jerzy T. Sadowski ◽  
Eike F. Schwier ◽  
...  
Keyword(s):  
Dirac Point ◽  
Electronic States ◽  
Quantum States ◽  
Photoemission Spectroscopy ◽  
Flat Band ◽  
Strongly Correlated ◽  
Dirac Cone ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Topological Materials ◽  
Photoemission Study

AbstractFlat band electronic states are proposed to be a fundamental tool to achieve various quantum states of matter at higher temperatures due to the enhanced electronic correlations. However, materials with such peculiar electronic states are rare and often rely on subtle properties of the band structures. Here, by using angle-resolved photoemission spectroscopy, we show the emergent flat band in a VSe2 / Bi2Se3 heterostructure. Our photoemission study demonstrates that the flat band covers the entire Brillouin zone and exhibits 2D nature with a complex circular dichroism. In addition, the Dirac cone of Bi2Se3 is not reshaped by the flat band even though they overlap in proximity of the Dirac point. These features make this flat band distinguishable from the ones previously found. Thereby, the observation of a flat band in the VSe2 / Bi2Se3 heterostructure opens a promising pathway to realize strongly correlated quantum effects in topological materials.

scholarly journals Development of a soft X-ray angle-resolved photoemission system applicable to 100 µm crystals

2011 ◽  
Vol 18 (6) ◽  
pp. 879-884 ◽  
Author(s):  
Takayuki Muro ◽  
Yukako Kato ◽  
Tomohiro Matsushita ◽  
Toyohiko Kinoshita ◽  
Yoshio Watanabe ◽  
...  
Keyword(s):  
Electronic States ◽  
Spot Size ◽  
Optical Microscope ◽  
Photoemission Spectroscopy ◽  
Beam Spot ◽  
X Ray ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Clear Band ◽  
Sample Position

A system for angle-resolved photoemission spectroscopy (ARPES) of small single crystals with sizes down to 100 µm has been developed. Soft X-ray synchrotron radiation with a spot size of ∼40 µm × 65 µm at the sample position is used for the excitation. Using this system an ARPES measurement has been performed on a Si crystal of size 120 µm × 100 µm × 80 µm. The crystal was properly oriented on a sample stage by measuring the Laue spots. The crystal was cleavedin situwith a microcleaver at 100 K. The cleaved surface was adjusted to the beam spot using an optical microscope. Consequently, clear band dispersions along the Γ–Xdirection reflecting the bulk electronic states were observed with a photon energy of 879 eV.

Direct evidence of metallicity atZnO (0001¯)−(1×1)surfaces from angle-resolved photoemission spectroscopy

2010 ◽  
Vol 81 (23) ◽  
Author(s):  
L. F. J. Piper ◽  
A. R. H. Preston ◽  
A. Fedorov ◽  
S. W. Cho ◽  
A. DeMasi ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Photoemission Spectroscopy ◽  
Angle Resolved Photoemission Spectroscopy

Performance of the BL03U beamline at SSRF

2020 ◽  
Vol 27 (5) ◽  
pp. 1388-1394
Author(s):  
Z. P. Sun ◽  
Z. H. Liu ◽  
Z. T. Liu ◽  
W. L. Liu ◽  
F. Y. Zhang ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Energy Range ◽  
Photon Energy ◽  
Vacuum Ultraviolet ◽  
Resolving Power ◽  
Photon Energy Range ◽  
Photoemission Spectroscopy ◽  
Theoretical Estimation ◽  
Shanghai Synchrotron Radiation Facility ◽  
Angle Resolved Photoemission Spectroscopy

The vacuum ultraviolet beamline BL03U with a photon energy range from 7 eV upwards has been constructed at the 3.5 GeV Shanghai Synchrotron Radiation Facility. Equipped with an APPLE-Knot undulator, this beamline is dedicated to angle-resolved photoemission spectroscopy. An energy-resolving power of higher than 4.6 × 104 has been achieved in the photon energy range 21.6–48 eV, which is almost the same as the theoretical estimation.

Temperature-Dependent Change of Correlated Electronic States in Yb4As3and Yb4(As1-xSbx)3Probed by High Resolution Photoemission Spectroscopy

1998 ◽  
Vol 67 (10) ◽  
pp. 3552-3560 ◽  
Author(s):  
Shigemasa Suga ◽  
Akira Ochiai ◽  
Takashi Suzuki ◽  
Hideyuki Harada ◽  
Akira Sekiyama ◽  
...  
Keyword(s):  
High Resolution ◽  
Electronic States ◽  
Photoemission Spectroscopy ◽  
Temperature Dependent ◽  
Dependent Change

Spin Polarized Photoemission from Fe On CU(100)

1991 ◽  
Vol 231 ◽  
Author(s):  
D.P. Pappas ◽  
K.-P. KÄmper ◽  
B.P. Miller ◽  
H. Hopster ◽  
D.E. Fowler ◽  
...  
Keyword(s):  
Low Energy ◽  
Photoemission Spectroscopy ◽  
Universal Curve ◽  
Exchange Splitting ◽  
Attenuation Length ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Minority Spin ◽  
Spin Polarized ◽  
The Difference ◽  
Majority Spin

AbstractThe spin resolved electronic structure of ultra-thin Fe films on Cu(100) was investigated using spin polarized angle resolved photoemission spectroscopy. All exchange splitting of the Fe ∆s band of 2.5 eV is observed for photon energies between 20 and 30 eV. ∆ peak at 6 eV binding energy which has been previously identified as a many-electron resonance was observed only after contamination of the films with oxygen. In addition, the spin dependent attenuation lengths for electrons in Fe were measured at 11, 19, and 40 eV above Ef. The attenuation length for the minority spin electrons was found to be shorter than that of the majority spin electrons. The difference between the two attenuation lengths was shown to increase at low energy. Short attenuation lengths of ≃3 monolayer were measured at II eV. The large increase of the attenuation length at low energy which is expected from the “universal curve” is not observed in Fe.

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