Journal of Theoretical and Applied Physics (JTAP) Spin–lattice coupling in iron-pnictide superconductors: a model for possible continuous phase transition Volume 6 (2012) Issue 1, November and December 2012 2023 11 17 Spin–lattice coupling in iron-pnictide superconductors: a model for possible continuous phase transition 10.1186/2251-7235-6-38 EN Chinedu E Ekuma Department of Physics, Computational Material Physics Group, University of Port Harcourt;Department of Physics and Astronomy, Louisiana State University Ephriam O Chukwuocha Department of Physics, Computational Material Physics Group, University of Port Harcourt Michael C Onyeaju Department of Physics, Computational Material Physics Group, University of Port Harcourt Journal Article 2023 11 17 AbstractA systematic study of the dependence of the local magnetic moment, M, on the Fe-Pn layer separation has been carried out. Within the Ehrenfest classification of orders of phase transition, we propose a continuous (>2) phase transition for studying the dependence of M on the Fe-Pn layer separation. Our model is tested with available experimental data.