Thermal behaviour of monoclinic zirconia at low temperature by XRPD Full Pattern Analysis

Monoclinic zirconia was studied by X-ray Powder Diffraction (XRPD) in the range from 10 K to room temperature. Silicon was added to the powder as an internal standard and the data obtained at different temperatures were analyzed by the Full Pattern Analysis (FPA) derived from the classical Rietveld method. The non linear trend of the thermal expansion of the unit cell and the behaviour of the Debye-Waller factors was discussed. It was pointed out how the use of an internal standard and the proposed FPA can greatly improve the accuracy of the cell parameters, without loss of structural information even in the presence of strong peak overlapping. The structural data obtained (at room temperature: P21/c, a = 5.1511(2) angstroms, b = 5.2027(2) angstroms, c = 5.3187(3) angstroms, β = 99.215(4)°, Vc = 140.70 angstroms3, Z = 4, GofF = 1.28) were compared with the results of previous works on the same material.