welcome back to the second part of our demonstration
of the new innovations that have been implemented on the aeris platform
in this section i will demonstrate to you the transmission diffraction solution
that we have introduced together with the parallel plate collimator and transmission is generally
used for lowly absorbing materials to counteract the transparency effect in reflection measurements
and so this is typically performed on organic materials uh such as pharmaceuticals for example
and also today i would like to demo that by two measurements first the conventional brackpentano
measurement and then a transmission diffraction measurement introducing our new sample holders
for let's start with the optical setup first so again we have newly introduced
new optical component on the diffracted beam path before we only had one fixed anti-scatter
slit tunnel but now we have introduced a new design for the fixed anti-scatter slit on the
diffracted beam side that allows you to introduce different sizes of anti-scatterer slits we have
nine millimeter which is conventionally used for the bregman tonneau measurements and for
transmission we've introduced two millimeter as you have seen before and five millimeter as well
so on the incident beam side we we have also introduced a new component which is a combined
anti-sketchup slit and filter that reduces scattering at lower ranks lower diffraction angles
so i've already set up the instrument for the measurement but before i would
like to start the measurements i want to also show you our new sample holders
those are our dedicated transmission sample holders which allow you to measure
powders that are prepared between foils in this case it is a conventional milo foil between
two frames and they can introduce into the system like this and the second type
of folders that we've introduced is a capillary sample holder and this is how it looks like so
basically you can mount the capillary in the center of the sample holder and also mention
measure it in our conventional spinner the advantage of these type of sample holders is
that you can use it use them in combination with the sample changer and more importantly you can
even combine them with conventional brackpentano measurements and this is what i'm going to demo
now so i have prepared an uh endometadine and lactose mixture here in a conventional
bracken tonneau holder so this is one of our newly designed low angle diffraction holders
and i've also prepared it between milo foils in our transmission frame holders
and what i'm going to do now is i'm going to start two sequential measurements first the
brackpentano measurement that is then immediately followed by the transmission measurement
so in order to protect the samples i'm just going to mount the cover of our sample changer
and i've pre-prepared two measurement programs the brackmantana measurement program is roughly
going to take two minutes 20 seconds and the transmission measurement program is going to take
five and a half to six minutes so and what i'm going to do now is i'm going to start the first
measurement here so the sample is then picked up by the gripper again put into the sample loader
and then it is introduced into the instrument
and then while this measurement is already starting i can also add the second measurement and
put it to the queue so that means once the first measurement is done the second measurement will
automatically start after the gripper has unloaded the first sample and reloaded the second sample
after the two measurements are done we're going to compare the raw data again
to show the benefit of the transmission application for lowly absorbing samples
and here you can already see how the raw data is built up you see quite good peak intensities
so now the first measurement is finished the sample is being loaded out of the system back
to the sample position one and our transmission sample is now being introduced into the system
and now the transmission data is collected as a pure to theta scan
similar to grazing incidence measurements and for that i'm going to switch to the second sample
position to see the data being built up again so now we are transmitting through the sample
which is why this application is called transmission diffraction
so that allows us to prepare very small amounts of sample and very thin samples as well
and by that we can reduce this transparency effect because generally organic materials are
very lowly absorbing so that means what happens is that during a bragpantano measurement again
what we face is we face a continuous increase in sample penetration with higher measurement angles
which means what we will see is we will see a continuous shift in
the peak positions at higher angles and also peak broadening in addition to that
for sample preparation for breckpentano measurements we usually also introduce quite a lot
of preferred orientation which is highly reduced in transmission measurements when you prepare
the samples between foils or even battering capillaries what is important to note here is
is that i didn't have to change any any optics between the two measurements because i set up both
measurements in a way that they can be measured sequentially which is very convenient because
it allows you to do to combine different types of samples and different types of measurements
in the same measurement batch without having to interact with the system
so now also our transmission measurement is done and we will have a look at the data shortly
um just to be clear so the also the capillary holders it could be measured in
the same sequence but since the measurement principle is exactly the same as for the
as for the foil measurement uh i decided not to demo that in that section today but we will show
data in the following webinars and where we have a much more closer look to data collection and
also data analysis so but now just i would like to compare the two data sets that we just collected
and again for that i open data viewer and import it to scans
so and this is the comparison and at first sight the two data sets they look very similar so the
red one being the transmission measurement the blue one being the breckpentano measurement
however if you look closer what you do see is is that with increasing peak positions
you have an increasing shift in the peak position in the brake pentano measurement
so this is very clear when you compare the first peak there the peak shift is quite small but you
can already see that the peak is broader but then the higher the measurement angle the larger the
peak shift and this is a result of the sample transparency which is just a result of the low
absorbance of the sample itself meaning that at higher diffraction angles in the brackpentano
geometry the beam penetrates the sample to a deeper level which means that the average
measurement the average sample height in the measurement geometry is getting lower and lower
and lower so this is one of the big benefits also in the data what you see is that the relative peak
intensities are different and that is a result of the preferred orientation that is introduced duri
due to the sample preparation in the bregbentano sample holder because we have to press the sample
in order to get the flat sample surface so that means if you compare the two data sets to the
to the relative peak intensities from the databases what you will see is
is that the transmission measurement is actually much closer to the expected
relative peak intensities from the database then for example a breakfantano measurement
and yeah hopefully i was able to show you the benefits of the two applications
and that's it from my site thank you very much for your attention
you