Antiferromagnetic spin sequence

Because of its huge y-value (265mJ/molK ) PuAlj fits into the heavy-fermion sequence in the Kadowaki-Woods plot (Kadowaki and Woods 1986). Trainor et al. (1976) assumed that antiferromagnetic spin fluctuations dominate the low-temperature behaviour of PuAlj magnetoresistance experiments would be interesting in this respect. However, the " Pu isotope should be used for such low-temperature measurements to avoid self-heating problems. 

Replication degenerates to a random production of sequences in the limit q- j and corresponds to the limit r->oo, the case of maximum disorder. Direct and complementary replication (see also part C) are the analogs of ferro- and antiferromagnetic cases of the spin system. In the range q < 1 we have K<0, which corresponds to the condition pj<0 for ferromagnetic interaction. For complementary or plus-minus replication, we have... 

The ESR spectrum of the fully reduced anion, PV2 Wio04o (Figure 7), has the 15-hne pattern ((g) = 1.95, (a) = 53 G) expected for the interaction of the unpaired electrons with two vanadium nuclei. Observation of the half-field (Am, = 2) transition in the spectrum of the solid potassium salt confirms the triplet state of the species responsible for the spectrum in Figure 7. It seems very likely that those isomers (1,2 and 1,6 with V-O-V groups) which are responsible for the 15-line spectrum of the mixed valence complex would have antiferromagnetically coupled spins in the fully reduced anion. The remote isomers with vanadium atoms separated by O-W-0 (1,4 and 1,5) or O-W-O-W-O (1,11) sequences are therefore probably responsible for the triplet state ESR spectrum. Further ESR and magnetic susceptibihty measurements are planned on individual isomers. 

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