Ultrafast demagnetization in buried Co80Dy20 as fingerprint of hot-electron transport

•Laser induced generation of ultrashort hot-electron pulses in magnetic multilayer system.•Control of temporal delay and stretching of photoexcited hot-electron pulses traveling through a magnetic multilayer system.•Element-resolved monitoring of hot-electron induced ultrafast demagnetization in ferrimagnetic rare-earth/transition metal alloys.