Anton Paar HTK 1200N, Справочное руководство

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7 Handling the Sample Holder and Sample
B40IB006EN-D 35
7.2.2 Solid Samples
Simply place solid samples into the groove of the
sample carrier.
The alignment equipment respectively the align-
ment stage allows you to compensate for the differ-
ence in height between sample and sample holder
groove.
TIP: Make sure that the contact surfaces between
sample carrier and top of the sample holder body
are free of dust and sample residues to provide for
a good thermal contact!
7.3 Temperature Validation
The two most important aspects for non-ambient
XRD are a highly uniform temperature in the sample
and a reliable temperature measurement. Both con-
ditions are fulfilled in the HTK 1200N:
• The design of the oven provides a high tem-
perature uniformity in the interior and conse-
quently guarantees a homogeneous
temperature distribution in the sample.
• The sample temperature is measured and con-
trolled with a Pt10Rh-Pt (type S)
thermocou-
ple . Its tip, which is the most temperature-
sensitive part, is located right underneath the
sample position . This set-up provides a very
good correspondence between the measured
temperature and the actual sample temperature.
TIP: A possible temperature deviation in the
HTK 1200N is not only influenced by its design, but
also by the thickness, thermal conductivity, emissiv-
ity of the sample and the thermal contact of the sam-
ple to the sample holder.
To account for temperature deviations in heating at-
tachments for non-ambient X-ray diffraction, a tem-
perature calibration should be performed.
Temperature calibration can be done by observing
known phase transitions: either melting points or
more preferably solid-solid phase transitions.
For some information on this issue refer to e.g. "In-
dustrial Applications of X-ray diffraction", edited by
F.H. Chung and D.K. Smith, Marcel Dekker Inc.,
2000, pages 891-901.
Alternatively the thermal expansion of known ma-
terials e.g. oxides such as MgO or alumina can be
used to calibrate the temperature.
The thermal expansion data of different materials
are collected in "Thermophysical Properties of High
Temperature Solid Materials", Y.S.Touloukian et. al,
Macmillan, New York, 1977.
TIP: Make sure that the heating of the sample is
performed slowly to prevent that the sample is de-
tached from the sample carrier and to guarantee
temperature equilibration of the sample.
Please note that there are currently no standard ref-
erence materials available for the calibration of non-
ambient XRD attachments.
NOTICE
Risk of damage
Make sure that the materials of the HTK 1200N
are chemically resistant against the sample and
reaction products! Please refer to
Appendix A .