Maximizing spin Hall magnetoresistance in heavy metal/crystalline metallic ferromagnet multilayers with opposite spin Hall angles

) generation and its reciprocal effects. Moreover, spin accumulation is enhanced at Pt(3 nm)/annealed NiFe interfaces after capping with a Ta layer, which functions as a spin sink in a certain thinner thickness range. With the cooperative interaction of choosing the proper Ta's thickness and annealing NiFe layers, the maximum SMR is obtained. Our results pave the way for rational interface engineering to enhance SMR for developing high-efficiency spintronic devices.