J. Phys. IV France 07 (1997) C1-591-C1-592
Heat Capacity and Neutron Diffraction of Low Doped Fe3-xZnxO4A. Kozlowski1, Z. Kakol1, R. Zalecki1, K.S. Knight2 and J.M. Honig3
1 Department of Solid State Physics, University of Mining and Metallurgy, al. Mickiewicza 30, 30-059 Krakow, Poland
2 ISIS, RAL, Chilton Didcot, Oxfordshire, OX11 0QX, U.K.
3 Department of Chemistry, Purdue University, West Lafayette, IN 47907, U.S.A.
We report on the heat capacity and neutron diffraction studies of Fe3-xZnxO4 (w<0.04) series. Adiabatic heat capacity measurements, performed on single crystals, confirm our earlier observations that in the range x<0.012 the Verwey transition is of first order, whereas for 0.012<x<0.035 the transition character changes to second order. The change of transition order is accompanied by the clear difference in heat capacity baselines below Verwey transition temperature Tv. The time-of-flight neutron diffraction data were collected at the High Resolution Powder Diffractometer in ISIS in the T range 4-240 K for two Fe3-xZnxO4 samples with x falling within first and second order regime. The comparison of spectra for both samples shows that second order sample undergoes much smaller structure change than that observed for first order sample what was suggested by our heat capacity measurements results.
© EDP Sciences 1997