Anton Paar TTK 600, Справочное руководство

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8 Performing a Measurement
52 D52IB001EN-G
8.3.3 Background of the foil materials
Another factor that has to be kept in mind for the
right choice of the foil material is the background of
the foils. The foil should be chosen in a way that the
ROI (region of interest) does not overlap with signal
of the foil.
The background of the different foils is summarized
below:
Fig. 54: Transmission measurements of the used foil
materials in TTK 600
The Kapton foil shows two peaks in the low 2 θ -re-
gion at ~ 4.4 and 5.7°. The first one can be attributed
to the Kapton foil on the housing of TTK 600 (It is
also visible for all other measured foils).
The Nickel foil shows strong reflections at 44.5 and
51.9° 2
θ whereas graphite shows a medium intense
reflection at 26.6° and an amorphous reflection from
42.3 to 47.4° 2
θ .
The thicknesses of the used foil materials are as fol-
lows:
From the comparable low values of transmission for
Nickel it can be clearly seen that Nickel should only
be used as foil material if the background of graphite
does interfere significantly with the ROI from the in-
vestigated substance.
8.3.4 Foil Materials for the Battery Sample
Holders
The battery sample holders (both reflection and
transmission) contain Kapton foils to ensure the gas
tightness of the sample holder. As the thermal con-
ductivity of Kapton is relatively poor, additional
graphite foils can be provided to ensure the smallest
possible difference between the temperature on the
CCU 100 and the actual sample temperature. The
graphite foils must be used in combination with the
Kapton foils to ensure the gas tightness of the sam-
ple holder.
The absolute temperature differences for the differ-
ent foil combinations on the reflection and transmis-
sion holders in a nitrogen atmosphere are shown
below:
Fig. 55: Difference between the set temperature of the
CCU 100 and the actual sample temperature for dif-
ferent foil combinations of the battery sample holders
under N
2
atmosphere.
The temperature differences are fairly small across
the entire measured range (typically < 5 %) when
only a Kapton foil is used and smaller when the
graphite foil is also used. However, especially in the
case of the reflection battery sample holder, use of
the graphite foil leads to strong additional diffraction
peaks so this must also be considered.
In addition, the use of the graphite foil leads to a re-
duction in the diffracted intensity. For both the re-
flection and transmission battery sample holders,
the diffracted intensity is ~ 68 % of that obtained
when only Kapton foils are used.
Due to the influence that the graphite foils have on
the diffraction pattern (see chapter 8.3.3) and the re-
duced X-ray transmission, it is recommended in
most cases to use only a Kapton foil; graphite foils
are optionally available when the smallest possible
temperature deviations from the displayed tempera-
ture of the CCU are needed.
Foil material
Thickness/
µm Transmission
for Cu-radiation
Kapton 25 96
Nickel 10 43
Graphite 80 86