Magnetization reversal and tunable bipolar magnetization switching in Ni20Mn3B6 alloy

•A unique negative magnetization phenomenon with two compensation points is founded in Ni20Mn3B6 alloy.•Based on the XRD test, this phenomenon is arising from the two non-equivalent types of Mn atoms in the alloys.•A tunable bipolar switching of magnetization between positive and negative values without any decay has been observed. Magnetization reversal has attracted more and more interests due to its applications on spintronic devise and magnetic storage materials. However, the magnetization reversal is rarely studied in the non-rare earth intermetallic compounds. In this work, we have found that the Ni20Mn3B6 alloy exhibits the magnetization reversal phenomenon with the decreasing temperature at low applied fields (H ≤ 100 Oe), accompanying with two compensation temperatures. Further analysis showed that the first compensation temperatures is due to the competition between the two different interactions of Mn atoms that occupy two different positions. The second one is arising from the rotating of the moment on demand of Zeeman energy. Based on this phenomenon, a tunable bipolar switching of magnetization between positive and negative value has been found in the alloy between two compensation temperatures, which can be applied in the spintronic devices and magnetic storage materials.