File:The magnetization of cobalt as a function of the temperature and the determination of its intrinsic magnetic field (1911) (14590997520).jpg

Identifier: magnetizationofc00stif (find matches)
Title: The magnetization of cobalt as a function of the temperature and the determination of its intrinsic magnetic field
Year: 1911 (1910s)
Authors: Stifler, William Warren, 1883-1954
Subjects: Cobalt Cobalt Magnetic induction Cobalt Magnetic fields Theses
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Contributing Library: University of Illinois Urbana-Champaign
Digitizing Sponsor: University of Illinois Urbana-Champaign

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at 600°C. From that point on up to 1050°C thedifference between the two curves at any temperature is practicallyconstant, lying between 20 and 21. Hence, if the theoreticalcurve is shifted up 20 divisions it will coincide with the exper-imental curve in the interval 500°C to 1050°C. This is shown bythe double circles in Figure 20, In the interval above 1070°C the experimental curve hasthe general form of the hyperbola. This agrees with the resultsdeduced from equation (S). From the data at 1104°C we can calculate the molecular ■ j field and the moments of the elementary magnets. For this temper-j ature we have T = 1104° + 273° = 1377° Abs.Im= 163.6 x £.77 = 1435He I I/He <m» m» » ^ mm m- *— mmm~ m~ «w»ai«»m0«-:«n»«--«»&~eMr- »-»»™»o— tt-<v»MR»^ on 1400 11.1 0.00793 2400 16.6 0.00692 3050 23.3 0.00764 Mean value of l/He = k = O.OO753 Substituting these values in equation (9) - page - we have vj 1 x 134E? 0.00753 1377 - 154£ = 61#0 - 52 -
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- 59 - H©no © Hm = NIm = 61 So x 1435 = £,#70,000From (11) we have M = UL© The value of R to he used is that corresponding to one molecule, viz. R = 1.36 x 10**16. Hence m v - 3 x 1.36 x 10~16 x 134g61&0 x 1435 ■ 6.21 x 10~20 The number of elementary magnets per cubic centimeter from (12) is = 2.31 x 1022 The number of atoms making up an elementary magnet is given by(13), viz. n = d = _aNm NAmH The values to be substituted are:- d = £.77 Nf = 2.31 x 1022 =24 A = 59.00 mH = 1.61 x 10 giving ^77 n = 59.00 x 2531 x 10** x 1.61 x 10^ = 4.01 Hence four atoms of cobalt make up the elementary magnet. Thevalue 4.01 is far more nearly an exact integer than the accuracy ofthe data would lead us to expect, end this is strong evidence ofthe accuracy of the value of © • It is interesting to compare these results with thosegiven in Table VII on page 50. The results are summarized below. - 60 - Table X.- * - loll Jm © N HIm = Hm x»020 B » Pe 1^60 2120 756°C 3,^50 6,560,000 5,15 2 4

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