Effect of substrate temperatures on the electrical resistivity of thermally evaporated Mn thin films

The anomalous low temperature resistivity of thermally evaporated α-Mn thin film

“…Comparing these results to the previous work [3] it is seen that substrate temperatures play a crucial role in sample quality. For example, in the previous work [3] a sample prepared with a substrate temperature of 523 K gives a residual (or excess) resistivity of 1.00 mOm, whilst that of 323 K gives a residual (or excess) resistivity of 2.20 mOm.…”

“…According to Craig and Goldburg [5], the Né el point T N of an antiferromagnet can be defined by the position of singularity of the qr/qT versus temperature curve. The line width of the transition corresponding to the difference in temperature of the first minimum to that corresponding to the maximum is 124 K, which is large as compared to the previous results [3] and consequently this is expected to show a broad transition. Accordingly, the Né el point could be approximately anywhere in the range (95715) K from these results.…”

“…Preparation of the sample and measurement of the resistivity by the van der Pauw technique [4] is given by Boakye et al [3]. A He 4 cryostat of conventional design was used for these experiments as described by Boakye et al [3].…”

“…For example, in the previous work [3] a sample prepared with a substrate temperature of 523 K gives a residual (or excess) resistivity of 1.00 mOm, whilst that of 323 K gives a residual (or excess) resistivity of 2.20 mOm. It is interesting to note that with the sample of substrate temperature 323 K, the resistivity maximum or the ''cusp'' vanishes.…”

“…Consequently the low temperature resistivities have been explained in terms of spin fluctuations, obeying a T 2 at low temperatures. Boakye et al [3] have studied the effect of substrate temperatures on the electrical resistivity of three samples of manganese thin films, from 300 to 1.4 K, using the van der Pauw four probe technique. The films were grown by thermal evaporation onto glass substrates held at 523, 323 and 77 K, respectively in a bell jar held at 6 Â 10 À 6 Torr.…”