WHAT’S tougher than finding a needle in a haystack? Finding a single atom inside a crystal – but a US team has now cracked it. The feat should give scientists a better understanding of materials whose properties depend on how atoms are arranged within them, such as metal alloys and catalysts.
Maria Varela and colleagues at Oak Ridge National Laboratory in Tennessee used an electron microscope to spot individual atoms of lanthanum hidden in a crystal of calcium titanate. The key to finding the interlopers was a technique called aberration-correction. This narrows the electron beam used to scan the sample, increasing…
