The Competition between Staggered Field and Antiferromagnetic   Interactions in Cugeo3:Fe
  The EPR spectra along different crystallographic axes for single crystals of CuGeO3 containing 1% of Fe impurity have been studied in the frequency range 60-360 GHz at temperatures 0.5-30 K. The analysis based on the Oshikawa-Affleck (OA) theory suggests that the temperature dependences of the line width and g-factor are formed as a result of the competition between interchain antiferromagnetic interactions and staggered Zeeman energy. It is found that staggered magnetic moments in CuGeO3:Fe are located predominantly along b axis. 
S.V Demishev, A.V.Semeno, A.A.Pronin, N.E.Sluchanko, N.A.Samarin,   H.Ohta, S.Okubo, M.Kimata, K.Koyama, M.Motokawa