Antiferro-ferromagnetic transformation in LaMnO3 under neutron irradiation

Using the methods of neutron and X-ray diffraction analysis and magnetic measurements, polycrystalline samples of LaMnO3 were studied before and after irradiation with fast neutrons (En ≥ 1 MeV) at a fluence Φ = 5.5 × 1023 m–2. It was established that irradiation leads to the partial (∼5%) mutual disordering of the “lanthanum” and “manganese” sublattices. Ion displacements emerging at such radiation-induced disordering lead to the destruction of the Jahn–Teller mode Q2 responsible for A-type antiferromagnetism development in the initial sample. As a result, the antiferromagnet canted ferromagnet magnetic transformation is observed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)