CriticalPeakRelaxationRate#
Description#
The Critical Peak Relexation Rate is defined as:
where: - \(S_c\) - Scaling - \(T_c\) - Critical temperature - \(a\) - Critical exponent - \(B_1\) - is a non-critical background when \(x < T_c\) - \(B_2\) - is a non-critical background when \(x >= T_c\)
When fitting users should set \(T_c\) as the temperature at which the peak occurs. Users are also asked to supply two values for \(B_g\). The first should be the value of y when x is at it’s minimum. The second should be the value of y when x is at its maximum, minus the first background value.
Examples#
An example of when this might be used is for examining the Chiral-like critical behaviour in antiferromagnet Cobalt Glycerolate[1] or in muon spin relaxation studies of critical fluctuations and diffusive spin dynamics in molecular magnets[2].
Attributes (non-fitting parameters)#
Name |
Type |
Default |
Description |
|---|---|---|---|
Delta |
Properties (fitting parameters)#
Name |
Default |
Description |
|---|---|---|
Scaling |
1.0 |
coefficient for scaling |
CriticalTemp |
0.01 |
coefficient for critical temperature |
Exponent |
1.0 |
coefficient for critical exponent |
Background1 |
0.0 |
coefficient for non-critical background when x < Critical Temperature |
Background2 |
0.0 |
coefficient for non-critical background when x > Critical Temperature |
References#
[1] Pratt, F.L, Baker, P.J., Blundell, S.J., Lancaster, T., Green, M.A., and Kurmoo, M. (2007). Chiral-Like Critical Behaviour in the Antiferromagnet Cobalt Glycerolate. Phys. Rev. Lett., Vol 99 Issue 1, 017202 doi: 10.1103/PhysRevLett.99.017202. [2] Pratt, F. et al (2009) Muon spin relaxation studies of critical fluctuations and diffusive spin dynamics in molecular magnets. Physica B: Condensed Matter, Volume 404 Issues 5–7, pp585-589 doi: 10.1016/j.physb.2008.11.123.
Categories: FitFunctions | Muon\MuonModelling\Magnetism
Source#
C++ header: CriticalPeakRelaxationRate.h
C++ source: CriticalPeakRelaxationRate.cpp