Antonio dos Santos | Chemist Profiles


Antonio dos Santos

Antonio dos Santos, Instrument Scientist

  • Oak Ridge National Laboratory
  • B.S./M.S., Materials Engineering, New University of Lisbon, Portugal; Ph.D., Materials Science, University of California, Santa Barbara.
Antonio dos Santos works in the following areas:

Nuclear Chemistry  ∎  Materials Chemistry  ∎  Government

Antonio dos Santos has worked as an instrument scientist at the Oak Ridge National Laboratory (ORNL) for five years. He looks after a one-of-a-kind neutron diffractometer that is dedicated to high-pressure crystallographic research. He makes sure that the diffractometer is operating smoothly, and he provides scientific support to researchers who use this instrument.

Instrument users come from all over the U.S. and around the world, and some have never worked with this type of instrument before. Others are more experienced, but may require special adaptations or experimental conditions to perform their work. Scientists who use the diffractometer rely on dos Santos for help with experimental setups and data collection conditions that will yield the most useful information for their purposes. "We are all about supporting the users and their science," he says.

His graduate work focused on the materials science of magnetoelectric oxides, and he received his Ph.D. in 2002. Afterward, he did a postdoctoral research fellowship on the structures and properties of luminescent oxides. After a second postdoctoral fellowship, which relied heavily on high-pressure neutron diffraction at Oak Ridge, dos Santos was offered a staff position to continue his work on the high-pressure diffractometer.

What's a typical day on the job like?

A big part of my job is working with users. When they are setting up their projects, I help them evaluate what experiments are doable, and how they can set things up to best get the information they need from their data. I help them determine if our instrument is the best one to do their experiment, or if another instrument would be more suitable. We figure out the best sample configurations, data collection parameters, and software setup for their purposes.

When I am not directly engaged with an experiment at the instrument, I help users with their data or writing new proposals, and I help review the manuscripts they are preparing for publication. I participate in designing new improvements for the instrument, and doing mostly what is considered “office” work.

When it comes to providing support to users at the beamline (the experimental area where the diffractometer is located), then the pace really changes. The day is spent at the instrument, getting set up, loading samples in pressure cells or other devices, and aligning them in the neutron beam, training users in beamline operations and how to use our software. Finally, we make sure the data looks as it should — the neutron beam isn't hitting the edge of the high pressure cell, the instrument hasn't become misaligned, or similar problems.

When I'm not assisting visiting users, I work on my own research projects. I also think about ways to develop the instrument to keep it relevant for the user communities we support — geologists, chemists, condensed matter physicists. We also support theorists in validating their models. Almost all the research is basic research, because most applied research projects don't need the extreme high pressures we use.


I do data reduction using Mantid, software developed by a consortium of neutron scattering facilities. I extract crystallographic structural information from the powder diffraction profiles using Fullprof and GSAS to perform Rietveld refinement. I use the Python programming language to customize the data collection setup, to put all the other software together, and automate the data extraction from the hundreds of data files that one experiment can generate.

Describe your work environment.

The instrument where I work is situated in a walk-in concrete enclosure called a hutch. The hutch also contains detectors, electronics racks, optical systems, pressure chambers, and other sample environments (think bunker-meets-spaceship environment). The hutch shields the people outside from the neutrons that are scattered while an experiment is in progress. You set up your experiment inside, and then go outside to monitor and control your data collection using computers in a nearby office. When I am not at the instrument, setting up experiments, I sit in my office, working on the computer, mostly helping users either understand their past experiment or prepare for the next one.


We put in a lot of hours, including nights and weekends, during times where there is neutron production at the facility. This happens twice a year, in 4.5-month cycles. We work especially long hours when we are responsible for running an experiment. Those times when I'm on call as the "local contact", I can't plan much of anything outside of work, because I can be called in to help at any time. I do go home every night, but I can't handle everything from home, and sometimes I have to go back to the lab to resolve an issue that has come up.

The rest of the time it gets more normal, but that's when we try to get our own projects done, schedule travel for conferences, and visit other labs, so you really stay busy all the time.


I am away from the office on travel between one and five days each month (sometimes more, sometimes less), visiting university departments to make presentations and collaborate with the researchers there, and going to conferences. I sometimes visit scientists at other facilities to see how they do things. Occasionally, I serve on Ph.D. thesis committees for graduate students who use our instrument.

What do you like most about your job?

Because I work on a scientific instrument that welcomes users from all over the world, I have the opportunity to work daily with experts from a number of different fields of research. I find it a privilege to engage in scientific discussions with other scientists, and I have a front row seat to witness great science in the making. On the other hand, I am also encouraged to pursue my own scientific interests and remain engaged with my collaborators, so for me it’s a win–win situation!

What's your best productivity trick?

I automate and simplify all that is repetitive, as I easily get tired of repeating the same process over and over. I always want (and need) to spend more time on the new stuff that keeps showing up.

What's the best career advice you've received?   

Whenever you are engaged in conversation, always try to listen longer than you speak.


I think that curiosity and a broad scientific background are key when you work in this environment and have to remain excited about 20 different scientific experiments that you have during the year.


I try to keep my to-do list tidy. I really try to deal with the small tasks as soon as they come, as they often take much less time to complete than thought

What is your favorite ACS resource?

I think the conferences and the ACS publications are really useful, as they really provide a broad window on what's happening all over in the word of chemistry.


Whenever you are engaged in conversation, always try to listen longer than you speak."