共查询到20条相似文献,搜索用时 15 毫秒
1.
K. Lawniczak-Jablonska J.J. Jia L. Lin M.M. Grush T.A. Callcott A. Asfaw J.A. Carlisle L.J. Terminello F.J. Himpsel D.L. Ederer J.H. Underwood R.C.C. Perera 《Applied Physics A: Materials Science & Processing》1997,65(2):173-177
1-x MnxS (where 0.05<x<1) were measured as the energy of the exciting radiation was tuned across the S and Mn-L2,3 absorption edges of these compounds. Strong resonance peaks in Mn-L emission spectra and the systematic appearance of new
spectral features in S-L emission spectra were observed. Partial substitution of Zn by a magnetic Mn ion results in strong
hybridization of the Mn 3d orbitals with the sp band of the host semiconductor. A detailed study of resonant inelastic scattering
in the vicinity of the S and Mn-L2,3 absorption edges of these DMS is presented.
Received: 6 March 1997 相似文献
2.
L. Braicovich F. Borgatti A. Tagliaferri G. Ghiringhelli N.B. Brookes P. Ferriani C.M. Bertoni 《Applied Physics A: Materials Science & Processing》2001,73(6):679-686
We discuss the application of resonant inelastic X-ray scattering to the study of magnetic systems in the soft X-ray range.
To this end we distinguish two broad areas. In the first the layout of the experiment is such that the absorption magnetic
circular dichroism (MCD) is not zero. In the second the magnetisation is perpendicular to the incident helical beam so that
the absorption MCD is zero. In the first area we summarise published results on Fe-Co alloys and we present new data on Mn
impurities in Ni together with calculations. In the second area we summarise published results on Ni in Ni-ferrite with final
3s shell excitation and we present new results on Co-metal and Co in Co-ferrite measured with a new approach. This is based
on the incident energy dependence of the integral of the Raman spectrum in inner shell excitation (integrated resonant Raman
scattering). The potentialities and the limitations of the above methods are critically presented.
Received: 23 May 2001 / Accepted: 4 July 2001 / Published online: 5 October 2001 相似文献
3.
J. Nordgren P. Glans K. Gunnelin J. Guo P. Skytt C. Såthe N. Wassdahl 《Applied Physics A: Materials Science & Processing》1997,65(2):97-105
Accepted: 6 March 1997 相似文献
4.
S. Eisebitt A. Karl W. Eberhardt J.E. Fischer C. Sathe A. Agui J. Nordgren 《Applied Physics A: Materials Science & Processing》1998,67(1):89-93
F in the nanotubes, indicating that metallic nanotubes are present in the sample.
Received: 2 April 1998 相似文献
5.
Resonant inelastic X-ray scattering (RIXS) at the transition-metal K-edge is studied as a tool to detect the electronic structure in correlated electron systems. We, in particular, focus on the polarization dependence of RIXS intensity and symmetry of the electronic excitations. It is shown that by analyzing the polarization of the initial and scattered X-rays, the symmetry of the 4p orbitals are selected. Combined effects of the polarization of X-rays and the momentum transfer in the scattering are also studied. 相似文献
6.
7.
8.
Received: 16 March 1996 相似文献
9.
C.E. Gonzalez S.C. Sharma N. Hozhabri D.Z. Chi S. Ashok 《Applied Physics A: Materials Science & Processing》1999,68(6):643-645
Near-surface vacancy-type defects have been studied by positron beam spectroscopy in three boron-doped Si wafers; a control
sample, second sample exposed to atomic hydrogen in electron cyclotron resonance (ECR) plasma, and a third sample annealed
at 500 °C following plasma treatment. From the analysis of the Doppler broadening spectra, measured as a function of positron
implantation depth, we obtain positron diffusion lengths of about 100 and 250 nm for the damaged layer and bulk of the wafer,
respectively. For the plasma-treated wafer, our measurements provide a defect density of about 5×1017 cm-3.
Received: 4 September 1998 / Accepted: 5 January 1999 / Published online: 28 April 1999 相似文献
10.
A. Nilsson N. Wassdahl M. Weinelt O. Karis T. Wiell P. Bennich J. Hasselström A. Föhlisch J. Stöhr M. Samant 《Applied Physics A: Materials Science & Processing》1997,65(2):147-154
2 and CO on Ni(100), benzene on Ni(100) and Cu(110), and glycine adsorbed on Cu(110). New types of molecular states are observed
which are directly related to the surface chemical bond. The long-accepted Blyholder model which is based on a frontier orbital
concept cannot explain our results for N2 and CO chemisorption. We find it necessary to offer a new picture where changes in the whole molecular orbital framework
have to be considered. We show that both π and σ type interactions are important in describing the bonding in benzene to metal
surfaces. The future prospect is illustrated by the adsorption of the simplest amino acid, glycine, on Cu(110). The adsorbate
has four different atomic centers where X-ray emission spectra are obtained, providing a unique view of the local electronic
structure.
Accepted: 6 March 1997 相似文献
11.
G.S. Chang J.H. Son K.H. Chae C.N. Whang E.Z. Kurmaev S.N. Shamin V.R. Galakhov A. Moewes D.L. Ederer 《Applied Physics A: Materials Science & Processing》2001,72(3):303-306
We have used ion-beam mixing to form Si nano-crystals in SiO2 and SiO2/Si multilayers, and applied photoluminescence and soft-X-ray emission spectroscopy to study the nanoparticles. Ion-beam mixing
followed by heat treatment at 1100 °C for 2 h forms the Si nanocrystals. The ion-beam-mixed sample shows higher PL intensity
than that of a Si-implanted SiO2 film. Photon and electron-excited Si L2,3 X-ray emission measurements were carried out to confirm the formation of Si nanocrystal in SiO2 matrix after ion-beam mixing and heat treatment. It is found that Si L2,3 X-ray emission spectra of ion-beam-mixed Si monolayers in heat-treated SiO2 films lead to noticeable changes in the spectroscopic fine structure.
Received: 20 November 1999 / Accepted: 17 April 2000 / Published online: 5 October 2000 相似文献
12.
Kim YJ Hill JP Benthien H Essler FH Jeckelmann E Choi HS Noh TW Motoyama N Kojima KM Uchida S Casa D Gog T 《Physical review letters》2004,92(13):137402
We report a resonant inelastic x-ray scattering study of charge excitations in the quasi-one-dimensional Mott insulator SrCuO2. We observe a continuum of low-energy excitations, the onset of which exhibits a small dispersion of approximately 0.4 eV. Within this continuum, a highly dispersive feature with a large sinusoidal dispersion (approximately 1.1 eV) is observed. We have also measured the optical conductivity, and studied the dynamic response of the extended Hubbard model with realistic parameters, using a dynamical density-matrix renormalization group method. In contrast to earlier work, we do not find a long-lived exciton, but rather these results suggest that the excitation spectrum comprises a holon-antiholon continuum together with a broad resonance. 相似文献
13.
H.A. Dürr M. Münzenberg W. Felsch S.S. Dhesi 《Applied Physics A: Materials Science & Processing》2001,73(6):693-696
The magnetic domain configurations of Fe 3d spins in Fe/CeH2 multilayers were measured by soft X-ray resonant magnetic scattering. The interface region could be probed by setting up
X-ray standing waves due to the multilayer periodicity. By resolving first- and second-order magnetic scattering contributions,
we show that the latter probe directly the magneto-crystalline anisotropy which is dominated by the Fe interface layers causing
a spin reorientation transition when the temperature is lowered.
Received: 30 May 2001 / Accepted: 4 July 2001 / Published online: 5 October 2001 相似文献
14.
利用软X射线共振非弹性散射谱(resonant inelastic soft X-ray scattering, RIXS)对3d过渡金属硫化物中的硫化锰(MnS)电子结构进行了研究.通过分析Mn2+的2p63d5→2p53d6→2p63d5二次光子过程,得到了共振非弹性散射谱中的两类非弹性峰,d-d电子跃迁和电荷转移(charge-transfer)跃迁.这两部分跃迁分别共振增强于L边附近及伴随峰附近.基于Hartree-Fock方法的多重态计算分别模拟了原子近似下和立方体Oh对称群下共振非弹性散射谱及吸收谱.计算得MnS实际晶体场10Dq值介于0.80eV—0.85eV之间.对MnS和MnO CT跃迁差异的讨论表明MnS较强的CT跃迁来源于其较窄的能隙宽度.
关键词:
软X射线共振非弹性散射
软X射线吸收谱
d-d跃迁
电荷转移 相似文献
15.
Using synchrotron radiation a new surface sensitive spectroscopy has been applied to determine the local structure of the first surface oxide layer formed on the Si(111) surface. The Surface Soft X-ray Absorption (SSXA) spectra have been measured. From the analysis of the X-ray Absorption Near Edge Structures (XANES) we have extracted structural information. We have first determined that bulk amorphous SiO has a characteristic microsopic structure, which cannot be described by the random alloy or microcrystalline (Si + SiO2) mixture models. The oxide layer formed on the Si(111) surface by ground-state molecular excitation in ultra high vacuum at temperatures (~700°C) approaching the oxide dissociation point has this unique SiO local structure. Such SiO layer not formed at room temperature is expected to be present in the SiSiO2 interface grown at high temperature. An electronic transition to empty states at the SiSiO2 interface has been observed. 相似文献
16.
Pieter Glatzel Junko Yano Hendrik Visser Weiwei Gu Stephen P. Cramer 《Journal of Physics and Chemistry of Solids》2005,66(12):2163-2167
A study of the Mn K absorption pre-edges in oxides using resonant inelastic X-ray scattering (RIXS) spectroscopy is presented. The energy transfer dimension enhances the separation of the pre-edge (predominantly 1s to 3d transitions) from the main K-edge and a detailed analysis is thus possible. The RIXS spectra are sensitive to the Mn spin state. The technique thus yields detailed information on the electronic structure that is not accessible in conventional K-edge absorption spectroscopy. The line splittings can be understood within a ligand field multiplet model, showing the importance of (2p,3d) two-electron interactions that give rise to the spin-sensitivity. 相似文献
17.
R. Krause-Rehberg H.S. Leipner T. Abgarjan A. Polity 《Applied Physics A: Materials Science & Processing》1998,66(6):599-614
1-x CdxTe after post-growth annealing. The experiments on defect generation and annihilation after low-temperature electron irradiation
of II-VI compounds are also reviewed. The characteristic positron lifetimes are given for cation and anion vacancies.
Received: 19 November 1997/Accepted: 20 November 1997 相似文献
18.
Y.F. Shek C.C. Ling C.D. Beling S. Fung 《Applied Physics A: Materials Science & Processing》2002,74(2):233-237
Positrons from a radioactive source are implanted into a reverse-biased metal–semiconductor contact and are drifted back towards
the contact by the internal electric field where they trap into voids and annihilate. The electric field dependent interface
annihilation fraction is monitored by way of the intensity of the long (∼400–500 ps) void lifetime component using positron-lifetime
spectroscopy. Unlike previous analyses of such systems a numerical model involving positron drift, annihilation and trapping
into the interfacial state has been constructed to describe the positron dynamics in the presence of the non-uniform junction
electric field. The use of the positron-lifetime technique in probing the internal electric field at buried contacts is thus
demonstrated. Results obtained using the numerical method for the Au, Al and Ni/Semi-Insulating (SI)-GaAs contact systems
are found to be consistent with the findings of previous studies on the Au/SI-GaAs system.
Received: 29 November 2000 / Accepted: 26 February 2001 / Published online: 25 July 2001 相似文献
19.
C.J. Glover T. Schmitt M. Mattesini M. Adell L. Ilver J. Kanski L. Kjeldgaard M. Agker N. Mrtensson R. Ahuja J. Nordgren J.-E. Rubensson 《Journal of Electron Spectroscopy and Related Phenomena》2009,173(2-3):103-107
Resonant inelastic soft X-ray scattering at the 3p resonances in crystalline Ge is presented. Both stationary and dispersive features are observed in a wide energy range above as well as below the ionization limits. These observations are in agreement with theoretical predictions based on a two-step model where the initially excited electron has no influence on the emission step. Excess population of states in the conduction band is found, and discussed in terms of attosecond electron dynamics. 相似文献
20.
本文介绍了火焰原子吸收光谱法测定光学新材料钛酸钡锶中钒和锶,研究样品制备、测试条件和共存元素干扰,本法的准确度和精密度均满意。 相似文献