Magnetic properties of LnMn(x)T(12-x) alloys in high magnetic fields

Earlier, preliminary magnetic data of LnMn(x)T(12-x) alloys with Ln = Ce-Nd , Sm and Y, and T = Fe, Co, Ni have been determined in magnetic fields up t o 140 kOe in the temperature range 1.7-300 K. In the present paper, the mea surements for selected compounds from the family mentioned above have been extended to magnetic fields up to 350 kOe at 4.2 K. The measurements up to 140 kOe were performed in permanent held whereas, above this held in pulsed field with a pulse duration of 10 ms. The measurements were carried out on bulk and loose-powder samples. All investigated materials exhibit ferro(fe rri) magnetic properties but without clear saturation and with tiny hystere sis. The results are discussed in terms of the magnetic coupling between th ree magnetic sublattice systems and the Mn-Mn separation. (C) 2001 Elsevier Science B.V. All rights reserved.