Magnetotransport properties of antiferromagnetic YBa2Cu3O6.25 single crystals
Abstract In-plane Δρ ab / ρ ab and out-of-plane Δρ c / ρ c magnetoresistivities of antiferromagnetic YBa 2 Cu 3 O 6.25 single crystals were measured in magnetic fields H applied along the ab -plane. Δρ ab / ρ ab is a superposition of two components: The first component is strongly in-plane anisotropic, changing sign from negative when H ∥ I to positive when H ⊥ I . The second component is positive, quadratic in H , and isotropic in the ab -plane. Δρ c / ρ c displays a fourfold symmetry upon in-plane rotation of the magnetic field, with maxima along the easy axes of antiferromagnetic spin ordering and minima along unfavorable directions of spin orientation (45° from the Cu–O–Cu bonds).