Soft Magnetic Properties of Fe-Ni-Nb Alloy Films
The relation between the soft magnetic properties and local anisotropy fluctuation measured by the dynamic differential susceptibility method in Fe-Ni-Nb alloy films was clarified and discussed in comparison with Fe-Si-Al alloy films. Fe-Ni-Nb alloy films with excellent soft magnetic properties, 5 MHz values of ¿eff = 6500 for 1000 Å thick films were obtained. For Fe-Si-Al alloy films, the magnitude of ¿eff = 6500 is proportional to 1/S2 (where S is a structure constant) and independent of the value of Hk, while for Fe-Ni-Nb alloy films, the value of S is about one-tenth of that in Fe-Si-Al alloy films, and the magnitude of ¿eff 6500 does not depend on S. Rather, this magnitude is dependent on the value of Hk, and is almost equal to 4¿Ms/Hk, obtained from a rotational magnetization model in a uniaxial single-domain particle.
Investigation of the Structure of Ferromagnetic Films by Means of the Differential Susceptibility
The differential susceptibility of thin polycrystalline iron–nickel-films has been measured. From the results the structure constant, S, could be determined. The experiments gave the same field dependence for the susceptibility as was expected by former calculations. The values for S, evaluated from the experiment, can be explained quantitatively by the mean crystallite diameter, the magnetocrystalline anisotropy, the magnetostriction constants, and the intrinsic stresses, if one uses the Doyle-Finnegan formula for the calculation. The measurements show quantitatively the existence of the intrinsic demagnetizing field, which has been predicted by micromagnetic calculations and which contributes to the whole effective field. 
 
 
 
Die differentielle Suszeptibilitat dunner Eisen–Nickel-Schichten wurde ermittelt und aus den Meswerten auf die „Strukturkonstante” S der Schichten geschlossen. Die Feldabhangigkeit der Suszeptibilitat stimmt mit fruheren theoretischen Vorhersagen uberein. Die experimentell ermittelte Strukturkonstante last sich quantitative aus der Kristallitgrose, den inneren Spannungen, den Magnetostriktionskonstanten und der Kristallitenergie erklaren. Die Messungen stellen einen quantitativen Nachweis des mikromagnetisch berechneten inneren entmagnetisierenden Feldes dar, welches zum gesamten Effektivfeld beitragt.
Immunization with Brucella melitensis Rev 1 against Brucella ovis infection of rams.
The efficacy of Brucella Melitensis Rev 1 vaccine (Rev 1) for the prophylaxis of Brucella ovis ram epididymitis was evaluated. Twenty-nine 3-month-old rams were vaccinated with 2 X 10(9) Rev 1 and 14 were revaccinated with 5 X 10(8) at 14 months of age. Six rams remained unvaccinated as a control group. All rams were challenged with 5 X 10(8) B. ovis at 21 months of age. Before being slaughtered 8 weeks later, only one vaccinated ram developed epididymitis while four of the six control rams developed testicular alterations. Genital and selected extragenital organs and lymph nodes were removed at slaughter and inoculated on selective media. B. ovis was isolated from 26.6% of the vaccinated rams, 21.4% of the revaccinated rams and 100% of control rams. Portions of epididymis, testes and vesicular glands were also used for pathological studies. More severe lesions were observed in control rams than in vaccinated ones. In conclusion, these results show that vaccination of young lambs, followed or not by revaccination, is a suitable method for the prophylaxis of B. ovis infection of rams.