No abstract

No abstract

The susceptibility-temperature relationship of carefully prepared manganese nitride Mn5N2 was measured over the temperature range —180°C to 530°C. The Curie-Weiss law χ=C/(T—θ) was found to hold, with θ=—1070 and C=0.0316 emu deg/g. The effective Bohr magneton number is 3.94 per Mn, and is in reasonable agreement with the theoretical value 3.87 for 3 unpaired electrons. This suggests that Mn5N2 behaves as a coordination compound with 4 electron-pair bonds. A new microvibration technique, particularly suitable for susceptibility investigations of materials available in small amounts, has been developed for the present work. The underlying principle is to modulate the magnetic field and to translate the periodic force on the material into a periodic displacement of an elastic strip. The force is measured dynamically in terms of a compensating electrostatic force, an electronic circuit being used as a null detector. Accuracy to 10—4 dyne is claimed.

LETTERS TO THE EDITOR recrystallized at 700°C. The essential nature of these traces and of the fJ phase are now under investigation. Some tentative explanation about the mechanism of hydrogen hardening phenomena in a fJ range and the details of experimental results will be shown in another paper.2

No abstract