| Autor: |
Martínez Sánchez H; Departamento de Física, Universidad del Valle, Meléndez, Cali A.A. 25360, Colombia., Hadjipanayis G; Department of Physics and Astronomy, University of Delaware, 217 Sharp Lab, Newark, DE 19716, USA., Pérez Alcázar GA; Departamento de Física, Universidad del Valle, Meléndez, Cali A.A. 25360, Colombia.; Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, Meléndez, Cali A.A. 25360, Colombia., Zamora Alfonso LE; Departamento de Física, Universidad del Valle, Meléndez, Cali A.A. 25360, Colombia.; Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, Meléndez, Cali A.A. 25360, Colombia., Trujillo Hernández JS; Departamento de Física, Universidad del Valle, Meléndez, Cali A.A. 25360, Colombia.; Facultad de Ciencias Naturales y Matemáticas, Universidad de Ibagué, Ibagué 730007, Colombia. |
| Abstrakt: |
In this work, the mechanochemical synthesis method was used for the first time to produce powders of the nanocrystalline Nd 1.1 Fe 10 CoTi compound from Nd 2 O 3 , Fe 2 O 3 , Co and TiO 2 . High-energy-milled powders were heat treated at 1000 °C for 10 min to obtain the ThMn 12 -type structure. Volume fraction of the 1:12 phase was found to be as high as 95.7% with 4.3% of a bcc phase also present. The nitrogenation process of the sample was carried out at 350 °C during 3, 6, 9 and 12 h using a static pressure of 80 kPa of N 2 . The magnetic properties M r , µ 0 H c , and (BH) max were enhanced after nitrogenation, despite finding some residual nitrogen-free 1:12 phase. The magnetic values of a nitrogenated sample after 3 h were M r = 75 Am 2 kg -1 , µ 0 H c = 0.500 T and (BH) max = 58 kJ·m -3 . Samples were aligned under an applied field of 2 T after washing and were measured in a direction parallel to the applied field. The best value of (BH) max ~ 114 kJ·m -3 was obtained for 3 h and the highest µ 0 H c = 0.518 T for 6 h nitrogenation. SEM characterization revealed that the particles have a mean particle size around 360 nm and a rounded shape. |
