Piezomagnetic Material Changes Magnetic Properties When Stretched

Piezoelectric materials, which generate an electric current when compressed or stretched, are familiar and widely used: think of lighters that spark when you press a switch, but also microphones, sensors, motors and all kinds of other devices. Now a group of physicists has found a material with a similar property, but for magnetism. This “piezomagnetic” material changes its magnetic properties when put under mechanical strain.

Magnetic experiment

Top: A piece of BaFe2As2 is stretched while magnetic measurements are taken (the copper wire coil is part of the NMR device). Lower diagram shows atoms in a plane, with black arrows showing how magnetic spins lie in plane and point in opposite directions. Grey arrows show how the magnetic spin of atoms shifts as the material is stretched.

Synchrony in Ecology: What Magnets Have To Do With Pistachios

By Kat Kerlin

Did you ever pass an orchard with branches bursting with flowers and wonder how the trees “know” when to blossom or bear fruit all at the same time? Or perhaps you’ve walked through the woods, crunching loads of acorns underfoot one year but almost none the next year.

Pistachios

A new study shows why pistachio trees are like magnets, mathematically speaking.

Scientists from the University of California, Davis, have given such synchronicity considerable thought. In 2015, they developed a computer model showing that one of the most famous models in statistical physics, the Ising model, could be used to understand why events occur at the same time over long distances.