Bruker Anton Paar, User Manual

Page: 22 / 136

General Remarks
22 DOC-M88-EXX268_V1_12.2016
The accuracy of temperature determination with MgO is ± 20 °C below 500 °C, ± 30 °C up
to 1000 °C and less than ± 40 °C up to 1400 °C. (0.001 Å change in lattice parameter cor-
responds to a temperature change of 17 °C).
Table 2.1: Reflections of MgO (a
0
= 4.2112 Å), CuK
α1
-rad. (* CuK
β
-rad.) at 30 °C
Bragg-angle [°] d-value [Å] HKL Intensity [%]
36.937 2.43163 111 4
42.917 (38.608*) 2.10564 200 100
62.304 1.48905 220 39
74.691 1.26982 311 5
78.630 1.21578 222 10
94.052 1.05281 400 8
105.734 0.96621 331 2
109.765 0.94172 420 19
127.285 0.85967 422 14
143.754 0.81051 511 4
2.2.2.1.1 Detailed Procedure for Temperature Determination
Put a small amount of MgO on the heater or the sample holder. Start a scan at 30 °C from
30 °C to 130 °C in 2θ. Use the program DIFFRAC.TOPAS [1] for refining the lattice con-
stant a
0
(a
0
= 4.2109(3) at 25 °C). Refine the parameters for lattice constant and height
(never together with the zero shift for 2θ). If the chamber height was adjusted correctly,
you should get a
0
= 4.2112 Å at 30 °C and zero for the height correction. Use this method
for all desired temperatures to determine the correct temperature (compensated for height
changes) as function of the indicated temperature by comparison with the literature val-
ues, T = [a
0
(T)‑4.2094] / 5.910 ·10
‑5
(all temperatures in °C, see figure Temperature de-
pendence of lattice parameter a0 of MgO [ } 23] ).