Resistance Paints the Secret Angles of a Magnetic Dance ⚡ экспресс
Scientists investigated how electrical resistance changes depending on the direction of a magnetic field in a special material. Usually, for antiferromagnets the signal shift is 90°, but here it turned out different from sample to sample — as if a compass pointed not north, but wherever it pleased. This unexpected discovery makes you wonder: what hidden magnetic forces are driving this process?
Using a method similar to spectroscopy (magnetic sensing), scientists pass a current through a multilayer film and observe the orientation of the microscopic magnetic arrows inside. Previously, everything was predictable: in some materials, the arrows aligned only along the current, in others—strictly across it. But in bismuth ferrite with a platinum coating, a glitch occurred. As the external magnet rotated, the resistance changed as if each arrow forgot the common alignment and chose its own angle—10°, 37°, 72°.
By measuring the magnitude of this chaotic signal, researchers hope to understand the cause of the entropic disorder. The solution promises the memory of the future: data will be stored not in bytes, but in twisted vortices of the magnetic field. By the way, bismuth ferrite is a two-in-one: it's both a magnet and an electric accumulator, changing properties at the slightest flip.
🎯 Bismuth ferrite is a multiferroic: it combines ferromagnetism and ferroelectricity, working as two materials in one.