The Nd self-diffusivity was studied in nanocrystalline Nd-rich Nd2Fe14B. From an analysis of the diffusion profiles, grain-boundary diffusion coefficients were deduced (table 5) which were similar to values observed for 59Fe diffusion in the same material. At temperatures above the intergranular melting transition, a second diffusion path revealed rapid diffusion in the liquid intergranular phase.

Grain-Boundary Diffusion of 147Nd in Nanocrystalline Nd2Fe14B. W.Sprengel, S.Herth, V.Barbe, H.E.Schaefer, T.Wejrzanowski, O.Gutfleisch, R.Würschum: Journal of Applied Physics, 2005, 98[7], 074314 (5pp)

Table 5

Grain Boundary Diffusion of 147Nd in Nd2Fe14B

 

Temperature(K)

D(m2/s)

623

7.1 x 10-18

688

5.1 x 10-16

773

1.1 x 10-13

860

2.6 x 10-12

873

1.7 x 10-11

947

4.0 x 10-11

948

1.5 x 10-11

950

3.8 x 10-11

958

2.4 x 10-11

963

1.7 x 10-11

968

1.8 x 10-11

973

1.3 x 10-11