Atom positions in steel

I was able to make some data sets available this year from work published in 2004 and in 2017 showing how atoms arrange themselves in nanostructured steel (Super Bainite).

There are a couple of motivations for making the data sets available. Firstly it is good practice and makes it possible for others to analyse the data to check reproducibility of my work, and there is also possibility to extract further information. It also serves as a back-up for the data sets by putting them on internet, one of the best back-ups available… 🙂

Another is that, at the time of conducting these experiments a frustration of mine was that there was no [simple] way to view the positions without access to commercial software, for me, that was once I had left the facility I visited to undertake part of the work. Hopefully the sharing of atom position data will become more standard procedure in future, with the increasing sophistication of high-level computing languages and expansion of open software. This may allow new developments in reconstruction of volumes, analysis of the atom positions, and education of users; benefiting the atom probe field.

The data were collected by using a pulsed electric field concentrated on the tip of a needle made by electropolishing the steel sample. By pulsing the voltage both the time-of-flight and the position the projected atom hits a detector screen can be recorded. This can then be mapped back to the sample volume, allowing measurement of the composition of the steel with better than nanometre resolution. The technique is called 3D atom probe (3DAP) tomographic atom probe (TAP) or atom probe tomography (APT). This technique is related to field ion microscopy.

The volume studied include volumes from various crystal structures (BCC bainitic ferrite, FCC thin-film austenite, carbides such as Fe3C cementite) in the particular steel I was studying (nanostructured carbide-free bainite — see papers for details).

Data can be found here:

The papers describing the data can be found here:

I’m glad to make these data sets available, and hope they will continue to be available in the future from the Cambridge repository website.

At the time I did the experiments, only commercial software was available to view the atom probe data such as IVAS ivas, but today I believe it should be possible to view the atom positions using software such as 3depict 3d epict.


Employers of non-EU workers in UK

Read Rare Books online

Read pages of books from Shakespeare, Benjamin Franklin, Redouté, Galileo, Copernicus, Louis Renard, Kepler, Einstein, etc, etc.


Robert Hooke’s Micrographia from 1665 is one example of what can be browsed.

Example content from A page showing the head of a fly from Robert Hookes Micrographia.

Example content from A page showing the head of a fly from Robert Hookes Micrographia.

University research and collaboration with companies

This article is a bit confused it uses example of steel developed at Cambridge as the example of a component where University research has contributed to the airplane engine (correct) and then talks about how Rolls-Royce benefits from its network of University Technical Centres (UTCs) (also correct). However I don’t believe that any of the UTCs have competence in steel design, that work was done in  Harry Bhadeshia’s phase transformation and complex properties research group in Cambridge. This shows how Universities and Companies benefit from being flexible in their approach to collaboration.



80s tracks

These long forgotten 80’s track seem eerily familiar.

Superbainite on stage at Apollo theatre


Among the Yamabushi (Narrow Road Part 4)

Victoria Vardley on Matsuo Bashō, with some beautiful sketches.

Tsundoku bookcase

Back on the road with Bashō and his straw sandals…

One of the high points of his journey, figuratively as well as literally, was his pilgrimage to the 出羽三山(でわさんざん) Dewa Sanzan, three mountains of Dewa Province, which is a very sacred place in Shintō and Buddhism and in the 修験道(しゅげんどう) Shugendō mountain ascetic sect. This is a syncretic religion combining elements of Shintō and Buddhism, Taoism and other beliefs. Practitioners are known as 修験者(しゅげんじゃ) Shugenja or 山伏(やまぶし) Yamabushi (someone who prostrates himself in the mountains – the ‘bushi’ here is not the same as the word ‘bushi’ 武士(ぶし) meaning ‘warrior’). They go on foot through the mountains practising austerities, for example meditating while standing under ice-cold waterfalls – perhaps familiar to anyone who has read Mishima’s Sea of Fertility tetralogy? (Here is an interview with a Shugendō practitioner explaining some of the practices and the philosophy behind them.)

The three…

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