. The Bell System technical journal . 1000 2000 3000 4000 5000 6000 H, APPLIED FIELD IN OERSTEDS 7000 Fig. 7 — Measurement of x-™ ^nd k versus applied static field for three differ-ent discs, cut from the same ferrite block. large to be measured. Knowledge of A(l/Q)_ is not sufficient to determineXm — k in the resonance region because here the correction termA(l/Q)+(/?i — i?2) (cf. ecjuation 26) becomes comparable to the termA(l/Q)-(/?i + Rl) and is needed to compensate for the anomalous peakof the A(l/Q)_ curve. The loss parameters Xm ± k assume values ofthe order of 10~- below and above reso
. The Bell System technical journal . 1000 2000 3000 4000 5000 6000 H, APPLIED FIELD IN OERSTEDS 7000 Fig. 7 — Measurement of x-™ ^nd k versus applied static field for three differ-ent discs, cut from the same ferrite block. large to be measured. Knowledge of A(l/Q)_ is not sufficient to determineXm — k in the resonance region because here the correction termA(l/Q)+(/?i — i?2) (cf. ecjuation 26) becomes comparable to the termA(l/Q)-(/?i + Rl) and is needed to compensate for the anomalous peakof the A(l/Q)_ curve. The loss parameters Xm ± k assume values ofthe order of 10~- below and above resonance. The estimated error of themeasurement is 3 X 10~. 444 THE BELL SYSTEM TECHNICAL JOURNAL, MARCH 1957 O z< X o. 5C +1 ,,,,, .J,,,.......,.,... .x1:.:.:.:.:.:.:.>:.:M.:. \ 1 \ i 1 ,:-; ^ <,-a: 1 1 11 - 1 \ ■ \ \^r^^fc y X ^ ^^^_ <^^ ^y -J— .... -4 ^— - •••••.. ^ 1000 2000 3000 4000 5000 h,applied field in oersteds 6000 7000 Fig. 8 — Evaluation of xm ± k from measurements of A(l/Q)± for low-lossBTL ferrite, saturation magnetization 1300 oersted. Whereas it is possible to obtain good agreement between measuredand theoretical curves of Xm ± k from Polders relations (3), such anagreement cannot be obtained for Xm ± k from a comparison with(4). This discrepancy is assumed to be caused by the fact that Polderstheory was developed for single ferrite crystals and did not take intoaccount the random orientation of crystal axes in polycrystalline ma-terials, such as the ferrites used in these measurements. It is reasonableto expect a broadening of the resonance line and a departure from theLorentzian shape in polycrystalline ferrites; hence, the expression for
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