Tellurite And Fluorotellurite Glasses For Active And Passive

5. Crystallisation studies; MDO 139
state semiconductor detector. The counter / detector registers the diffracted beam
intensity in successive stages away from the direct beam [1].
The sample is mounted at the centre of a goniometer, and a motor rotates the
goniometer and substrate by an angle of θ, and the X-ray detector is coupled to move 2θ
[1]. The signal is recorded by data logging software attached to the instrument. Each hkl
(Miller indices) reflection recorded appears as a peak on the trace, with a height
depending on the intensity of the diffracted beam. The range of 2θ values, scan speed and
step size can be varied to achieve the desired resolution [1]. 2θ angles corresponding to
the peaks on the traces can be converted d-spacings using the Bragg equation (equation
(5.5)) [3].
5.2. Results
5.2.1. XRD
5.2.1.1. XRD of batch materials
XRD was performed on batch materials to assess phase purity. Fig. (5.3) shows an XRD
trace of the 99.9995% TeO2 obtained from Alfa Aesar. It can be seen from this trace, that
the TeO2 powder used in this study was phase pure, resulting in a match to JCPDS card
number 78-1714: TeO2, tetragonal, space group P43212. Table (5.1) shows the ten most
intense peaks with corresponding 2θ (observed and theoretical) and Miller indices.