# Experiments

## My very first first-author paper, published in Physical Review B!

The top of the published article

It’s really out! I’ve been working on this article ever since I finished my master’s, and it finally got published. It turned out super well – I am so happy about this! My first first-author article in a scientific journal!

This is basically our reporting on the old hard X-ray measurements that I got to do my master’s thesis on – measurements of the staging superstructure observed in several different samples of single crystal LSCO+O. The measurements were done at several temperatures from down to 5-10 K, up to room temperature – giving us the opportunity to see how the staging appears at different temperatures depending on the doping in the samples. We also reported on the observed cooling rate dependence, which was found to depend on the amount of Sr doping in the samples.

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## Article in Physical Review B!

Top part of the published paper

Astrid put together this awesome paper on the work she’s been doing the last years. I helped with a bunch of the experiments back when I’d just started my PhD, so it is great to get it published too!

As a short description, the article is about the field dependence of the interplanar magnetic correlations in our LSCO-O sample. We found that the applied field enhanced the magnetic moments and increased the interplanar correlations (though only between neighboring planes). Also, these interplanar correlations could apparently also be forced through a fast cooling instead of an applied field.

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It feels like I’ve been updating this blog way too rarely the last couple of years – and that’s also the case for the web site as a whole. The last couple of days I have been procrastinating a bit, and had some fun with re-coding parts of the page, and setting up statistics. Turns out, a lot of the notes collections and old hand-ins get a lot of traffic, and it’s interesting for me to look at statistics for this.

Since the last post, I participated in several workshops, courses, experiments and conferences. Worth mentioning was the ICNS conference in Edinburgh, Scotland, two summers ago (July 2013), and a very exciting experiment at IN12 (ILL, France) the same month.

I finished all my teaching responsibilities, after having been a course instructor in the Experimental Physics course three times (although the first time was before I started my PhD) and once in the Neutron Scattering course, plus a couple of smaller things at different summer schools. I’m also almost done with taking courses, since I participated in a large number of workshops during the first part of my studies. I’ve had over a year long hiatus from my studies due to personal issues, and am currently working on getting back, by finishing my master thesis so I can continue on the PhD plan I started back in March 2012. Hopefully this will be over with in the beginning of this summer.

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## My first beamtime at ESRF

We were lucky to get a few days of beamtime on the hard X-ray instrument ID11 on the ESRF in Grenoble, France: from December 1st to 3rd. We measured reflections for several of our LSCO crystals at different temperatures, to get some of the beautiful superstructures in even better resolution that before.

A little look at what the data taking looked like:

I also got to see the mountains surrounding Grenoble from a new direction – I’d never all the way down south by the synchrotron on campus, and had no idea that there was a little roundabout down there either. Either way though, the view was awesome on the days we had sunshine!

A little panorama from ESRF

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## Another DMC beam time on LSCO+O, and a little PCMO

From November 21 to 28 we had another beam time at the DMC instrument at SINQ, where we measured reciprocal space maps for two of our LSCO+O crystals.

I arrived a couple of days early to align the samples, and had some very late nights because things didn’t want to work – as is seemingly the usual when aligning crystals… If nothing else, I got to entertain myself with how much the sample holders looked like little robots.

The measurements themselves went perfectly, and we had some extra time to put a powder sample of PCMO on the instrument in the end. Hurray for beautiful data to take home!

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## Some extra time on IN12

Since some of our last beamtime on the inelastic neutron instrument IN12 was wasted because of missing and non-prepared equipment, we got an extra piece of beam time, continuing the last experiment we did there in May. We had from June 30th to July 3rd, although the first day was really only to check the alignment on the sample – while the last day was only until the early morning.

## More cool airport visits!

On my way home, I had to switch planes in the Charles de Gaulle airport, which I’ve never done before. What interesting architecture they have! And there were security guards and police on segways, I’ve never seen that before…

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## Beam time on IN12

From May 11 to 17, I’ve been at the ILL in Grenoble, France, to do an experiment on the triple-axis neutron instrument IN12, where we did inelastic measurements on one of our LCO+O crystals.

We had to spend a whole day on the OrientExpress instrument to co-align our samples, since there were four of them to be used at the same time… It was a horrible puzzle to get them matching up, but we got it done!

The actual measurements on IN12 was done between May 14 and 17, and despite a lot of problems with some of the instrument components not being delivered on time (wasting us a lot of time in the end), we got some great measurements.

One absolutely awesome thing on this trip, was that one of our local contacts at the ILL managed to give us a little tour of the reactor hall. We got to have a look at all of the neutron instruments inside of the inner instrument hall, and we got to stand above the reactor and see the Cherenkov radiation. It was so beautiful. I’m sorry about not having any pictures for here, but their rules are pretty strict about taking photos…

## Some extra photo time in Frankfurt

On the way to France, I had a 4 hour layover between planes in Frankfurt airport, and I took the opportunity to walk around in the huge airport and take pictures of airplanes and fun architecture and decorations.

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## Working a couple of weeks at the Rutherford Appleton Laboratory

From April 1st to 13th, I’ve been at the Rutherford Appleton Laboratory (RAL) in Oxfordshire, England, to work together with the instrument responsible at the SXD instrument. We’ve been working on my data analysis, but the main thing we did was do extra measurements on two different laboratory X-ray diffractometers on small shavings of the same LSCO+O crystal that we had on SXD. These data will help me get an even better overview of my superstructures, since the X-ray instruments can measure for higher $$q$$ than what we’ve previously been able to.

The two diffractometers were at ISIS (an Oxford Instruments Gemini diffractometer) and the Harwell Research Complex (an Oxford Instruments SuperNova diffractometer), right on the RAL campus, so it was super convenient. We got so much new data – on several different small pieces of the crystal – and at least some of them have really nice resolution. I can definitely use this further!

The Gemini instrument

I stayed at a cute lille Bed & Breakfast in East Hendred, a short ten minute bus drive from campus. The two cozy pubs provided some awesome meals for my dinners, and I felt super welcome there – I’ll be staying there every time I go to ISIS from now on. The guest house at campus is really, really not worth it compared to this place (it was basically the same price, for a way better room, and way better opportunities for dinner)!

## Beautiful London

On the first day, on my way to Oxfordshire, I took a little detour and spent a few hours in London. It’s the first time I’ve been in the city, and I spent my time walking around, mostly along the Thames – visiting the typical tourist spots like Elizabeth Tower, Trafalgar Square, the Tower Bridge, the Gherkin, and the Millenium Bridge at St. Paul’s Cathedral. I had a great time, and I’ll definitely return one day to have a look at some of the less visited places!

## A little side trip to Oxford

I spent one of my days working at the Bed & Breakfast in the morning, and then taking a short trip to Oxford in the afternoon. I visited some of the old colleges and had coffee and pecan pie at one of the (if not the) oldest coffee shops in Europe – Queen’s Lane Coffee House. I used one of those hop-on-hop-off tourist bus things, and they drove us around and explained how things used to work in the old days of the city. It was really interesting!

I stopped at the botanical gardens and had an ice cream while enjoying the beautiful Spring flowers. I also went to see the beautiful Renaissance dining hall at the Christ Church college, where they filmed the Harry Potter Hogwarts dining hall scenes: despite the long line and too many people, it was kind of fun to see.

## Weekend trip to bird-of-prey park and Stonehenge

On Sunday, April 7th, the local contact took me on a trip to a bird-of-prey park and Stonehenge, just to get out and do something, instead of sitting at the Bed & Breakfast working all weekend. It was super cool – and I’m really glad he suggested it!

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## My first ISIS beamtime

During the last six days, I’ve been in England, more specifically the Rutherford Appleton Laboratory in Oxfordshire, to do measurements on one of our LCO+O crystals (actually the same crystal that we did measurements on at DMC in Switzerland last month). I was at the SXD instrument, a time-of-flight neutron Laue diffractometer, where we measured at five different rotations of the crystal, each for both low temperature and room temperature.

We got a huge amount of data, and mapped out a large volume in reciprocal space. The number of superstructures we saw was really large, and so far we haven’t been able to get a full refinement of the data. The on-site peak integration software was really cool though, and seemed to do the job great – and the instrument scientist was extremely helpful.

All in all, a great experience, and I hope that I (probably with the help of the instrument scientist) will be able to get the superstructures solved.

Of course I also had a few minutes here and there to walk around and take some pictures:

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## Yet another beam time, now with students!

I just got home from Switzerland, once again, this time from a beamtime at the DMC powder diffractometer, where I was measuring on one of our LCO+O single crystal samples, in order to map out part of reciprocal space (both for the crystal aligned in the cb- and the ab-plane). It was some really cool measurements, and I think I’ve already found the front page image for my thesis!

I actually started out the trip with starting up a beam time at the RITA-II instrument, where a YMnO3 sample were to be investigated. That was also really exciting – and that experiment continued during my own DMC beam time as well (sadly I didn’t have time to follow it all the way though, but their results looked really cool!).

Some of the students from the neutron scattering course were down there with us, to follow the two experiments. That was really fun, but I hadn’t expected how hard it was to help them to understand everything, when I didn’t even understand half of it myself! Usually beam times are really tiring, but this really took the price!

The DMC data weren’t really the most perfect data to do structure refinement from (in the cb-plane we only got 12 structural peaks, and some of them were of really bad resolution), but we saw some cool temperature dependencies, and already have some new proposals out for TriCS and other instruments in order to explore those things more. We also got a friendly beam time of two days at the new EIGER instrument, which will be really cool to work with.

This trip also marked the end of the neutron course, although I still need to correct a few reports, and help a few more of the students with their final project. But all in all, it’s been fun teaching in the course, even though it has been quite hard at some times!

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## OrientExpress beamtime over

I’ve just returned from the Institute Laue-Langevin (ILL) in Grenoble, France, where I’ve been on a super-short beamtime at the neutron Laue instrument OrientExpress. This was my first time to the ILL, and I was going there on my own. That was confusing! The airport in Lyon has really bad signing, but I found my way (after a while of wandering around not understanding anything, I might add..).

I was measuring on two new LSCO crystals, to see how many single crystals was in them. Both of them actually came from one crystal, but it broke into two during the oxygenation process. It seems like they are possibly full single crystals, a great result, but they might have a splitting in the length direction (they are cylindrical) – which is kind of a mess to cut up. I guess I will have to do some X-ray Laue images to see if that is the case.

## The absolutely stunning rail station at Lyon-Saint Exupéry Airport

On the way back home, I went to the airport in Lyon a little early, to go explore the train station connected to the airport. I have never seen a more alien building – it’s absolutely stunning!

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## Another RITA-II beamtime

This was a hard couple of weeks! Just the day after getting home from the DanScatt meeting in Odense, I took a plane to Switzerland super-early in the morning, for a new round of beamtime at the RITA-II instrument at PSI.

Helium and nitrogen refill gives a lot of smoke

With a little help from Christof Niedermayer, I used the first couple of days to get our sample aligned and get it on a new holder (it was already aligned in the ac-plane from the last beamtime, but we needed it in the ab-plane with a certain tilt out of the plane). Astrid showed up Sunday to help. Unfortunately, somewhere in the research phase we had found the wrong diameter of the magnet we were going to use, and it turned out that we had to start all over with a much smaller holder! That was a huge setback, and we had to start almost all over with the alignment. We weren’t done yet when Linda showed up on Monday.

But we did get it working in the end, and did a lot of cool measurements on an incommensurate magnetic peak, and how it changed with applied magnetic field.

## A little weekend trip to Basel

Astrid went home after the first week, leaving Linda and I to finalize the experiment (even though I guess this experiment was mostly for her project). Luckily, it was possible to script a large amount of the scans, and we actually took a whole day off to go to Basel Saturday June 9th. That was a really great little trip, and we saw a lot of fun museums and architecture – especially the Tinguely museum was interesting, with so many odd sculptures!

Another fun thing that happened was that I met Ivana (who I met at the PSI summer school in 2011) in the instrument hall! She was at a beamtime at the SANS-I instrument, doing some measurements that I really didn’t understand. But we had a little time to get some coffee at talk things over, that was nice.

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## PSI detwinning beamtime

Yesterday, I returned from a long week in Switzerland, where I’ve been on a beamtime at the RITA-II instrument at the SINQ neutron source at the Paul Scherrer Institute (PSI).

I was there along with Astrid T. Rømer and Linda Udby, doing measurements on three different LSCO crystals. We tried detwinning them using magnetic fields, but it ended up not working at all.. Week well spent! Well, at least I got some training in aligning single crystals, and we did get some beautiful data.

We’ll have to look at some different techniques for measuring detwinning than neutron scattering (possibly dilatometry), before we want to do anything with neutrons again.