Hello,
There are two positions available in the ISIS Crystallography group:
FBU127 Instrument Scientist - Magnetic Diffraction
Department ISIS Department
Summary: We are looking for a highly motivated and independent scientist, who
will take the lead in commissioning WISH, develop
Dear Colleague,
Starting from cycle 2004/03 (April-May 2005), ISIS has started to offer a
Measure-by-Courier powder diffraction access mechanism to the GEM
diffractometer (XPRESS). This mechanism is aimed at new and infrequent users,
research programmes requiring only limited and/or
The Institute of Physics and the Faraday Division of the Royal Society
of Chemistry Neutron Scattering Group
Student and Young researcher bursaries available for
Neutron Scattering from Biological Systems
Cosener's House, Abingdon, OXON, 13-14 December 2004
The Neutron Scattering Group is
Autumn Meeting 2004
BCA Physical Crystallography Group
and the
IoP Structural Condensed Matter Physics Group
Neutron Scattering from Biological Systems
Cosener's House, Abingdon, OXON, 13-14 December 2004
Hosted at Cosener's House, Abingdon, OXON and supported by the PCG and
Rutherford
do you really have the
resolution even on
HRPD to see the diffuse scattering between Bragg peaks at
high Q ?
No we don't, but this is not the main point (by the way, we don't use HRPD
for PDF, it doesn't go to sufficiently short wavelengths). The main reason
to go to high Q is to avoid
I would argue that the Bragg
diffuse scattering both reflect the average instantaneous atomic
structure.
Yes. If you integrate over energy, the scattering function factors to a
delta function in time, corresponding to an instantaneous snapshot of the
spatial correlations. It is not a question
Two very good points by Armel:
all the very good PDF studies ...are made by using synchrotron data or
neutron data from spallation
sources
This is because they are the only means to get to high Q (i.e., high
resolution in real space) and sufficiently high resolution (in reciprocal
space)
The only truly unique PDF information is about *correlations*. Let's say
you have two bonded sites, both with anisotropic thermal ellipsoids along
the bond, and let's assume that the motion is purely harmonic. A sharp PDF
peak will indicate that the atoms move predominanly in-phase, a broad PDF
This is to answer the question from Alexandros:
The simplest approximation to the thermal expansion coefficient uses the
Debye or Einstein specific heat through the so-called Gruneisen formula
alpha=gamma*cv/(3*B*Vm)
where alpha is the linear expansion coefficient (1/3 of the volume TEC), B
ARGONNE NATIONAL LABORATORY/ISIS NEUTRON FACILITY
POSTDOCTORAL POSITION
The Materials Science Division at Argonne National Laboratory is seeking
candidates for a postdoctoral research associate position in neutron
diffraction. The successful candidate will be located predominantly at the
ISIS
Armil:
What criterion was adopted in the search? The following famous paper,
clearly of structural subject, is not on your list, but has 768 citations:
STRUCTURAL-PROPERTIES OF OXYGEN-DEFICIENT YBA2CU3O7-DELTA
JORGENSEN JD, VEAL BW, PAULIKAS AP, NOWICKI LJ, CRABTREE GW, CLAUS H, KWOK
WK
MICHIGAN STATE UNIVERSITY/ISIS NEUTRON FACILITY
POSTDOCTORAL POSITION
The Department of Physics and Astronomy at Michigan State University is
looking to fill a postdoctoral research associate position in the
local-structure-property relationship of complex oxides. The successful
candidate will
One important consideration on the issue of thermal parameters vs
occupancies is the Q-range (Q=4pisin(theta)/lambda) where useful information
exists. This is a function of the wavelength used, the resolution, the
complexity of the structure and the radiation (x-rays vs neutrons). The
best
Hi everybody:
Here is a useful couple of formulas for you neutron lot. They can be used
to predict in advance the Rietveld scale factor S for a TOF powder pattern.
I remind you that the profile intensity Y is defined as
Y=S|F|^2*H(T-Thkl)*L*A*E*O/Vo (see old GSAS manual, page 122). The
To answer Nail's question:
The Lorentz factor can be deduced from the expression of the integrated
intensity of a single reflection of a TOF powder pattern (in the absence of
attenuation):
I=[e(lam)*Omega]*[Vs/(32*pi*Vu^2)]*[lam^4*i(lam)]*[1/sin^3(theta)]*[Mhkl*|Fh
kl|^2]=
15 matches
Mail list logo
