Research Progress in Positive Magnetoresistance System

Over the last decade, the research of magnetoresistance effect and its mechanism has been one of the research hotspot of condensed matter physics. With the synthesis, preparation and discovery of a variety of new materials and new structural systems which possess magnetoresistance effect, its mechanism and the complexity of magnetoresistance system are also constantly being unfolded. In all kinds of magnetoresistance system and magnetoresistance effect which have been found, the research of positive magnetoresistance system and positive magnetoresistance effect, as a branch of the magnetoresistance research system, has special research value in the magnetoresistance system, magnetoresistance mechanism and application of new magnetoresistive devices. This pa- per reviews the progress of positive magnetoresistance system, magnetoresistance effect and its mechanism, shows the diversity of the positive magnetoresistance system, positive magnetoresis- tance effect and its mechanism, and briefly points out some common problems that need to be fo- cused in the studies of the positive magnetoresistance system.