21 Result(s)
-
Article
Mössbauer spectroscopy and magnetization of ordered arrays of ultrathin FePt nanodisks with perpendicular magnetisation
The purpose of this communication is to show that arrays of FePt with perpendicular anisotropy can be studied using energy-selective conversion electron Mössbauer spectroscopy. Magnetic nanostructures have bee...
-
Article
Phonon- and phason-dynamics in Al–Cu–Fe quasicrystals
The lattice dynamics of quasicrystals includes local phason jumps as well as phonons. Phason dynamics is important for the understanding of both the structure and atomic motion in quasicrystals, leading to sho...
-
Article
AlCuFe quasicrystals: Local electronic properties of these new industrial materials
We present room temperature 57Fe Mössbauer centre (isomer) shift and electric field gradient (EFG) results in the Al100-x-yCuxFey icosahedral-quasicrystalline (i-) and crystalline phases. We have investigated the...
-
Article
New high-resolution electrostatic electron spectrometer for conversion electron Mössbauer spectroscopy
The construction and performance of a new electron spectrometer using an electrostatic 90°-spherical deflection analyzer (SDA) is described. The spectrometer is suited for depth-selective conversion-electron M...
-
Article
Local magnetic properties of ultrathin ferromagnetic fcc-Fe-films on Cu(001)
Conversion electron Mössbayer spectroscopy (CEMS) on three monolayers (ML) thick metastable fcc-Fe(001) films grown epitaxially on a Cu(001) substrate under different conditions shows that these films are char...
-
Article
EFG studies of the AlCuFe quasicrystal and related structures
It is known that the structure and thermal stability of the AlCuFe icosahedral quasicrystalline (i-QC) phase is extremely sensitive to the exact composition. A stable, ideally quasiperiodic phase exists only a...
-
Article
CEMS and DCEMS investigations of Al-implanted iron
α-Fe surfaces were implanted with a nominal dose of 5×1017 Al ions/cm2 at 50 keV and a current density of about 3.7 μA/cm2. Samples of different shapes and thicknesses have been used in order to test the influenc...
-
Article
A review of two decades of the analysis of hyperfine parameter distributions in Mössbauer spectroscopy: Difficulties, progress and prospects
We present a review of the most used methods used to obtain hyperfine parameter distributions and discuss the mathematical problems. The Czjzek model and extensions for an EFG distribution in random systems is...
-
Article
The spin texture in Fe/Tb multilayers
Fe/Tb multilayers (ML) have been prepared in UHV. The layer thickness for Fe was varied from 10 to 80 Å with Tb-layer thicknesses of 3.5, 7, 14 and 26 Å. Different substrate temperatures Ts between Ts=130 K and R...
-
Article
Hyperfine interactions in ultrafine amorphous Fe−M−B (M=Ni, Co) alloys
Ultrafine amorphous (Fe, Co, Ni) B powders have been prepared by a chemical reduction method. The influence of the Co and Ni atoms on the distribution of internal magnetic fields P(Bhf) has been investigated.
-
Article
On the Mössbauer site assignment in YBa2(Cu1−xFex)3Oy
The assignment of the four57Fe Mössbauer sites which are observed in Fe-substituted YBa2Cu3Oy is presented. We present a systematic study of highly-controlled samples with low Fe-concentration over the whole oxyg...
-
Article
CEMS-study of the interface in Fe/Cr multilayer systems
The magnetic hyperfine (hf.) fields at the Fe/Cr interface were analyzed in epitaxial Fe/Cr thin film structures of (100)- and (110)-orientation with monolayer resolution by means of in-situ57Fe Conversion Electr...
-
Article
Bi, Sn and Sb valence states in highT c (Bi, Pb/Sn, Sb)2Sr2Ca2Cu3Oy
The valence of Bi and its substituents Sn and Sb are investigated in the high temperature superconductor (Bi0.8X0.15Sb0.05)2Sr2Ca2Cu3Oy (often denoted 2223) where X=Pb or Sn. Pb and Sn are isoelectronic with the ...
-
Article
The magnetic transition in Fe-substituted hexagonal β-Al9SiMn3 phase
Recently we have studies β-Al9Si(Mn1−x Fe x )3 using Mössbauer effect spectroscopy withx=0.28 and discovered a new transition at about 80 K. Neutron diffraction studies down to l...
-
Article
A comparison of the57Fe EFG properties in the crystalline and quasicrystalline phases of the Al−Si−Mn system
We present here the determination of the distributionP(q) of the electric field gradient in Fe-doped Al−Si−Mn icosahedral and decagognal quasicrystals and in the related crystalline phases, using in-field Mössbau...
-
Article
The sign of the EFG in semiconducting and grain-oriented high-T c YBa2 (Cu1−x 57Fe x )3O y by Mössbauer spectroscopy
-
Article
Performance-improvement in57Fe-DCEMS by an optimized scintillation counter
Applications of DCEMS or ICEMS for UHV studies of surfaces and interfaces are often severely limited by long recording times. To clarify the practical means to shorten this time, we introduce the “statistical ...
-
Article
Poster contributions
-
Article
Sign determination of the57Fe electric field gradient in Al-based crystals and icosahedral quasicrystals
The icosahedral quasicrystals i-AlMn isomorphically suostituted by 28 at.% Fe or by (CrFe) are studied for the first time by in-field Mössbauer spectroscopy (MS) in order to determine the sign and asymmetry pa...
-
Article
Investigation of amorphous and crystalline Sc3Fe alloys
Amorphous Sc3Fe alloy has been prepared by splat-cooling with levitation melting. The quadrupole splitting distributions for Sc3Fe were determined from Mössbauer spectra: the zero-field distribution has a Gaussia...
