Sign reversal of angular dependence of Planar Hall Effect in La0.7Ca0.3MnO3/SrTiO3 ultrathin film

• Sign reversal of angular dependence of RPHE in LCMO ultrathin film (∼4 nm) is presented.
• Results add an important understanding to the concept regarding the strain induced reversal of RPHE.
• High field or low field switching devices can be fabricated using these materials.
• On the other hand, Planar Hall effect (PHE) shows extreme sensitivity to magnetic fields.
• Additionally, a low magnetic field sensing devices can be fabricated by using the sensitivity of PHE to magnetic field.

We have investigated the effect of strain on the transport and magnetic properties of La0.7Ca0.3MnO3 (LCMO) ultrathin films. Here, we present the observation of strain induced sign reversal of angular dependence of Planar Hall Effect (PHE) in LCMO ultrathin films (thickness ∼ 4 nm) deposited on SrTiO3 (001) substrate (STO). This observation of sign reversal in anisotropic magnetoresistance (AMR) was also reported by us (H. Sharma et al. APL, 105, 222406), previously. The sign reversal of AMR and angular dependence of PHE with magnetic field or temperature for the 4 nm thin film may be attributed to the increase in tensile strain in the plane of the thin film which in turn facilitates the rotation of the magnetization easy axis. High field or low field switching devices can be fabricated using these thin films.