


HRPT: HighResolution Powder Diffractometer for
Thermal Neutrons
Laboratory for Neutron Scattering, Paul Scherrer Institute
HRPT
PhysikPraktikum für Vorgerückte:
"Nachweis antiferromagnetischer Fernordnung mittels
Neutronendiffraktion"
"Determination of long range antiferromagnetic order by powder neutron
diffraction"
Antiferromagnetic (AFM) ordering of Mn spins in manganese
sulfide MnS or manganese oxide MnO will be determined by powder
neutron diffraction. These compounds crystallize in a rock salt face
centered cubic crystal structure. Manganese sulfide MnS shows a
transition to the AFM state with the propagation vector k=[1/2 1/2
1/2] at Neel temperature about 150K. The Mnspins forming planes
perpendicular to the body diagonal are ferromagnetically aligned,
whereas the spins in the neighboring planes are antiparallel.
During the practicum we will try to reproduce the one of the neutron
diffraction experiments performed during 19461951 for which C.G.
Shull was honored with the Nobel Prize in 1994. We will perform
neutron diffraction experiment with MnS using powder diffractometer
HRPT/SINQ. From the analysis of the nuclear and magnetic Bragg peak
intensities and positions we will verify the crystal and magnetic
structures of manganese sulfide and determine the size of the magnetic
moment on manganese.
Note: The practicum is performed during only one day at PSI. To perform the experiment effectively
and analyze the experimental data it is necessary to have basic theoretical background on mathematical
description of crystal structure and diffraction (reciprocal space, Brillouin
zone, structure factor, etc.)
Beschreibung des Praktikums
(pdf)
_
Some relevant lectures (by V. Pomjakushin).
"Magnetic structure determination from the combined use of representation analysis and magnetic crystallographic symmetry"
(pdf)
UFOX  Unveiling complex phenomena in Functional OXides, University of Salerno, 78 July 2016
"Magnetic order from neutron diffraction experiments: applications of representation decomposition and Shubnikov symmetry"
, as it is (pdf) , and
"Diffraction at swiss spallation source SINQ"
, as it is (pdf)
IUCr Congress Satellite Workshop on the Role of Magnetic Symmetry in the Description & Determination of Magnetic Structures, 1416 August, 2014, Brockhouse Institute for Materials Research, McMaster University, Hamilton, Canada (near Toronto)
"Multik magnetic order in Ca3Cu1Ni2(PO4)4: representation approach and Shubnikov symmetry"
, as it is (pdf) , and
Invited talk at IUCr congress August 512, 2014, Montreal, Quebec, Canada
"Symmetry constraints in solving magnetic structures by neutron diffraction: Representation analysis and Shubnikov groups"
, as it is (pdf) , and
"Introduction to experimental neutron diffraction" ,
as it is (pdf 41 Mb).
Lectures given at the MOTT PHYSICS BEYOND THE HEISENBERG MODEL
Master Class
, October 26th to 27th, 2013, Paul Scherrer Institut, Villigen,
Switzerland".
V. Pomjakushin ,
"Advanced magnetic structures: classification and determination by neutron
diffraction".
(Exercize)
Lecture given 24.03.2010 at the
ETHZ lecture course "Neutron Scattering in Condensed Matter Physics" of Prof. A.Zheludev.
"High Resolution Powder
Diffractometer for Thermal Neutrons."
(pdf 31 Mb).
Talk given at the AIC Information Day on "Large Facilities
for Crystallography Studies: Synchrotron and Neutron sources"
October 19th, 2009 , Paul Scherrer Institut, Villigen, Switzerland.
"Determination of the magnetic
structure from powder
neutron diffraction."
Lecture given at the "Workshop
on Xrays, Synchrotron Radiation and Neutron Diffraction
Techniques June 1822, 2008, Paul Scherrer Institut, Villigen,
Switzerland".
as it is (pdf 11 Mb)
,
compacted slides (pdf 9
Mb)
or
mov
V. Pomjakushin,
Last modified:
25 March 2010 19:54:49 CET

