Magnetic Behaviour of ``Lithiated'' Fe_2TiO_5

Authors: M. A. MADARE, S. V. SALVI

Abstract: Fe_2TiO_5 shows a spin glass transition at 53 K and is mainly known for its semiconducting nature. A `LiAl' pair is incorporated in Fe_2TiO_5 by high temperature solid-state reaction. Fe_2TiO_5 + xLiAlH_4 \frac{1000 °C}{24 hrs in atmosphere} \to Fe_2Ti_{1-x} (LiAl)_xO_5 x < x The presence and quantity of ``LiAl'' is confirmed by Inductively Coupled Argon Plasma (IACP) technique. The crystalline geometry is determined by X- ray diffraction and Fourier Transform Infrared (FTIR) spectroscopy of powders. It remains orthorhombic pseudobrookite. Certain reflections of Fe_2TiO_5 are observed to enhance progressively with the content of ``LiAl''. The magnetic hysteresis parameters are observed to depend on the content of ``LiAl''. Initial susceptibility and permeability are measured as a function of temperature. The magnetic order is discussed and explained. It is concluded that the pseudobrookite possesses a `spinel like network', which is strengthened by incorporation of ``LiAl''. It produces a weak long-range ferrimagnetic order in place of short-range antiferromagnetic order. Possible applications are discussed in the text.

Keywords: Pseudobrookite, Lithiation, Intercalation.

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