The influence of dynamic surface fields on the coercive field and energy loss of amorphous Co_70.3Fe_4.7Si_15B_10 ribbon

The M-H loops obtained under different magnetization conditions have been used in order to analyze the coercive field H_c and the energy loss per cycle E for the amorphous Co_70.3Fe_4.7Si_15B_10 ribbon. Applying the model for the influence of the surface fields Hp on the magnetization processes in amorphous ferromagnetic ribbons, we investigated the effects of the dynamic field H_p on H_c and E. It is shown that the influence of dynamic H_p on the M-H loop does not depend on the origin of H_c and E (static or dynamic). This result is important both for the future investigations of the magnetization processes in these materials and for the potential applications

Utjecaj dinamičkih površinskih polja na koercitivno polje i gubitke energije u amorfnoj vrpci Co70.3Fe4.7Si15B10

The M-H loops obtained under different magnetization conditions have been used in order to analyze the coercive field Hc and the energy loss per cycle E for the amorphous Co70.3Fe4.7Si15B10 ribbon. Applying the model for the influence of the surface fields Hp on the magnetization processes in amorphous ferromagnetic ribbons, we investigated the effects of the dynamic field Hp on Hc and E. It is shown that the influence of dynamic Hp on the M-H loop does not depend on the origin of Hc and E (static or dynamic). This result is important both for the future investigations of the magnetization processes in these materials and for the potential applications.Gubitke energije E po jednom ciklusu te koercitivno polje Hc proučavali smo analizom M-H krivulja dobivenih u različitim uvjetima magnetiziranja amorfne vrpce Co70.3Fe4.7Si15B10. Primjenom modela za utjecaj površinskih polja Hp na procese magnetiziranja amorfnih feromagnetskih vrpci proučavali smo utjecaj dinamičkih Hp na E i Hc . Pokazuje se da taj utjecaj ne ovisi o porijeklu Hc i E (statički ili dinamički) što je važna činjenica kako za daljnje istraživanje tako i za primjenu ovakvih materijala

Model magnetiziranja amorfnog feromagneta kojim teče struja

A recent model for the explanation of the decrease of coercive field Hc and the core loss E in amorphous ribbons carrying a direct current Jd has been extended in order to account for the effects of an alternating core current J. The model predicts a linear decrease of Hc with the amplitude J0 of J and the achievement of Hc=0 for J0 which is sufficient in order to release the domain walls responsible for Hc in the absence of the drive field H. The actual shape and frequency of the core current pulses appear to be immaterial as long as the condition J=J0 at H = 0 is fulfilled. The accurate measurements performed on the stress-free Co70.3Fe4.7Si15B10 and twisted Fe80B20 ribbons confirm the validity of the model. Some applications of the phenomenon are briefly discussed.Nedavno predloženi model za sniženje koercitivnog polja Hc i gubitaka energije u feromagnetskim trakama kojima teče istosmjerna struja Jd proširen je na izmjenične struje J. U slučaju izmjenične struje model predviđa linearno smanjenje Hc s amplitudom J(J0) te dostizanje Hc = 0 kod vrijednosti J0 koja je dostatna da oslobodi domenske zidove koji su odgovorni za Hc u odsustvu magnetizirajućeg polja H. Sam oblik i frekvencija J su nevažni dotle dok je J = J0 za H = 0 ispunjeno. Precizna mjerenja izvršena na nenapregnutoj Co70.3Fe4.7Si15B10 i tordiranoj Fe80B20 amorfnoj slitini potvrđuju valjanost modela. Ukratko su razmatrane neke primjene modela te posebno odsustva koercitivnog polja

The model for the magnetization of current carrying amorphous ferromagnets

A recent model for the explanation of the decrease of coercive field H_c and the core loss E in amorphous ribbons carrying a direct current J_d has been extended in order to account for the effects of an alternating core current J. The model predicts a linear decrease of H_c with the amplitude J_0 of J and the achievement of H_c=0 for J_0 which is sufficient in order to release the domain walls responsible for H_c in the absence of the drive field H. The actual shape and frequency of the core current pulses appear to be immaterial as long as the condition J=J_0 at H = 0 is fulfilled. The accurate measurements performed on the stress-free Co_70.3Fe_4.7Si_15B_10 and twisted Fe_80B_20 ribbons confirm the validity of the model. Some applications of the phenomenon are briefly discussed

Study of the position of the domain wall pinning centres within the Co_70.3Fe_4.7Si_15B_10 amorphous ribbons

Variations of the positions and strengths of the domain wall pinning centres within an amorphous Co_70.3Fe_4.7Si_15B_10 ribbon were studied by means of a model for the influence of the surface fields Hp on the process of magnetization of amorphous ribbons. The strongest pinning centres are situated close to the free surface of the ribbon and the strength of the pinning centres decreases towards its centre

Proučavanje položaja centara zapinjanja domenskih zidova u amorfnoj Co70.3Fe4.7Si15B10 vrpci

Variations of the positions and strengths of the domain wall pinning centres within an amorphous Co70.3Fe4.7Si15B10 ribbon were studied by means of a model for the influence of the surface fields Hp on the process of magnetization of amorphous ribbons. The strongest pinning centres are situated close to the free surface of the ribbon and the strength of the pinning centres decreases towards its centre.Korištenjem modela za utjecaj površinskih polja Hp na proces magnetiziranja amorfnih feromagnetskih vrpci proučavan je položaj i jakost centara zapinjanja unutar amorfne Co70.3Fe4.7Si15B10 vrpce. Rezultati mjerenja, dobiveni djelovanjem polja Hp samo na jednoj površini, pokazuju da se jači centri zapinjanja nalaze na površini koja u procesu proizvodnje nije bila u kontaktu s valjkom. Ta činjenica je važna za daljnje tretiranje uzorka radi poboljšanja mekih magnetskih svojstava amorfnih feromagnetskih vrpci

Influence of the successive annealing on the magnetization processes in Fe_73.5Cu_1Nb_3Si_15.5B_7 ribbon

The model for the influence of core-current generated field Hp on the magnetization processes in ferromagnetic ribbons has been employed for the detailed analysis of the M-H loops and the corresponding dM/dt vs. H curves for Fe_73.5Cu_1Nb_3Si_15.5B_7 alloy, successively annealed at different temperatures