Magnetic properties of manganese borides alloyed with nickel

The specific features are studied of the magnetic properties (magnetization curves, particular and limiting hysteresis cycles), in fields up to 15 ke and at a temperature of 81 K, of sintered specimens of borides Mnsub(3-x) Nisub(x)B4 in which coexistence of ferro- and antiferro-magnetism is assumed. The existence of vertically displaced particular hysteresis loops has been discovered and no of correlation has been found between: 1) the value of the coercive force, Hsub(c), and the amplitude of the strength of the magnetic field, Hsub(m), in which the limiting hysteresis loop is achieved; 2) between the characteristics of the magnetization curves and the hysteresis loops. These features are due to the fact that on remagnetization, the irreversible changes in magnetization are determined, not only by the mechanism described by the critical fields, Hsub(i)sup(o), (as in magnetization), but also by the mechanism described by the fields of start, or nucleation, Hsub(i)sup(s), whose role increases with the amplitude of the strength of the remagnetizing field, Hsub(m)sup(')