title: Symmetry analysis of the structural and magnetic phase transitions in 122 iron arsenides.
abstract: It is evident from the literature that the 122 iron arsenides, XFe(2)As(2) with X = Ca, Sr, Ba or Eu, undergo one or more phase transitions from a higher-temperature paramagnetic tetragonal structure in grey group I4/mmm1' to an antiferromagnetic structure with magnetic space group C(A)mca. Symmetry analysis is used to enumerate the possibilities for the transition (or transitions) between the higher- and lower-symmetry structures, and the results are used as a basis for comment on published experimental results.
authors.affiliation: School of Engineering, University of Newcastle, NSW 2308, Australia. chris.howard@newcastle.edu.au
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Howard
authors.forename: Michael A
authors.initials: MA
authors.lastname: Carpenter