STATIC LOW-FIELD SUSCEPTIBILITY MEASUREMENTS ON BETA-NI(IO3)2.2H2O

Static magnetic measurements on the β modification of nickel iodate, Ni(IO3)2.2H2O at fields mainly between 1 and 300 Oe and at temperatures between 2.20 and 20.5 K confirm that this compound is weakly ferromagnetic. For the description of the results two kinds of remanence, isothermal and thermomagnetic remanence, are distinguished, the latter arising when the sample is cooled through TN while a magnetic field is applied. A sharp peak in the initial slope χo of the magnetization curves is found at TN = 2.88 K. Below TN the apparent spontaneous magnetization σo decreases suddenly. Some possible mechanisms to explain this behaviour are indicated. It is shown that the present results could only be obtained by heating the sample to a temperature higher than TN before every series of measurements at a temperature below TN. © 1969.