Inverted hysteresis loops in annealed Co–Nb–Zr and Co–Fe–Mo–Si–B amorphous thin films

Abstract Amorphous CoNbZr and CoFeMoSiB films with uniaxial anisotropy were obtained onto Mylar and Kapton substrates, and magnetically annealed under a field transverse to the as-prepared easy axis. Annealed samples exhibited a remarkable behaviour: inverted loops with M r / M s M r / M s , the latter being found between the as-prepared EA and annealing field directions. Results are explained by considering non-collinear effective uniaxial and biaxial anisotropies acting on the mean magnetization.