Saturation magnetization iron metal with temperature

The extent of reduction of the precursors of catalytically active metals is usually assessed by (i) temperature-programmed reduction (ii) thermogravimetry (iii) release of hydrogen upon treatment with acid (iv) reaction with iodine and (v) determination of the saturation magnetization with ferromagnetic metals (iron, nickel, and cobalt). 

Alpha-iron (a-Fe). Between room temperature and a transition temperature of 769°C, pure iron exhibits a body-centered cubic (bcc) crystal lattice (a = 286.645 pm at 25°C). Alpha-iron is a soft, ductile metal with a density of 7875 kg.m l Alpha-iron is also ferromagnetic, with a saturation magnetization at room temperature of 220 A-m -kg , and the cubic anisotropy constants are = 4.7 x 10 J-m and = 1.5 - 3.0 x 10 J m Carbon exhibits a poor solubility in alpha-iron with a maximum content of 0.025 wt.% C at 723°C. It is important to note that the word ferrite describes a solid solution of carbon into alpha-iron, though it is sometimes improperly used to describe alpha-iron (Section 2.1.9) ... 

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