Degree of co valency

The magnetic susceptibility of protactinium tetrachloride has been measured between 3.2 and 296 K [25], as shown in Table 18.3, and exhibits a ferromagnetic transition at 182 2 K. A high degree of co valency has been suggested to explain this relatively high transition temperature. The magnetic susceptibility of protactinium tetraformate [26] has been measured from 80 to 300 K and follows... 

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