Phase Transition of a Random Magnet, Ni_pMg_(OH)_2

元データ 1975-08-15 社団法人日本物理学会


The magnetic phase transition of the mixed crystals of nickel and magnesium hydroxides, Ni_pMg_<(1-x)>(OH)_2, as randomly diluted magnets was investigated by measurements of the susceptibilities. The critical curve (phase transition temperatures versus concentrations, p) shows a terraced form in the concentration region below p∼0.4, which might reflect the quasi-two dimensionality of Ni(OH)_2. The critical concentration, p_c, is estimated as about 0.1. Furthermore, the dilution of Ni(OH)_2 by Mg(OH)_2 changes the values of θ/T°_<max> and X_M°(T=0)/X_m°_<max>, and the shape of the peak of the susceptibility, where T°_<max> is the temperature at which the susceptibility, X_M°, has a peak value, X_M°_<max>. These changes are interpreted as a result of the change of the spin arrangement in an ordered state depending on the concentration, p.


Tsujikawa Ikuji Department Of Chemisity Faculty Of Science Kyoto University
Enoki Toshiaki Department Of Chemistory Tokyo Inst.of Technology
Enoki Toshiaki Department of Chemistry, Faculty of Science, Kyoto University