DE1646808C3 - Ferromagnetic materials based on nickel ferrite or nickel-zinc ferrite - Google Patents

Description

'Nickel ferrite or nickel ferrite containing cobalt and vanadium,: §eke η η ζ eich η ct' dUrch dnc ZusamineBietzunc, ^ !! · ^^^ in MelailoxycUnteikn. from 48 to 50 mol percent, preferably from 49.2 to 493 mol percent, Fe ₂ O ₃ , from 22 to 49 mol percent NiO, 0.1 to 27 mol percent ZnO, 0.17 _; up to 1.5 mole percent CoO and 0.1 to 0.5 mole percent V ₂ O ₅ . . "'■', *

(Br

Eieeetchafteh I. One

The kind mentioned at the beginning of the series gives rise to the following favorable ien. ·. · ^ A

small ones and therefore, if possible, the beginning *

permeability uid of the loss factor in the largest possible frequency range;

2. A possibly small value of the temperature factor F of the ^ i ^ gspcrBteabilitilt, during the

Value £ ei difference «Jquot | ducks - ^ - in the considered

The invention relates to ferromagnetic materials for magnetic cores for use at Frequencies above 1 MHz, consisting of iron cobalt and vanadium containing N: c! Ie! Ferrite or nickel-zinc ferrite.

The ferrites of this type known from GS-PS9 U 795 have an iron content of more than 50% Fe ₂ O ₃ . They are very sensitive to magnetic impact.

It is also important that the initial permeability, _{μ /} , of these nuclei changes as little as possible with the temperature in the temperature range between 20 and 70 ° C. or at least between 20 and 55 ^° C. In connection with this, it is already known {FR-PS 11 85 406) to lower the temperature factor of the initial permeability in the temperature range mentioned by adding small amounts, for example 0.4 to 4.0 mol%, cobaite oxide, / CoO, to the nickel-half ferrites.

The temperature factor F of the initial equilibrium is a quantity obtained by dividing the temperature coefficient (TC) of the initial permeability (µ,) by this permeability, d. H.

l'i

-I _x )

'.-YE- r

is obtained.

In this form, Λ μ represents the difference between the values of the initial pernlesibility of the at the temperatures ty and V ₁ , while μ, the

i; -Wcit; .ifcf bsi 20 ⁰ C measured initial parmeability ■ i daritelli ^ ■.

W ~ £, £ & etesfsSis is known to reduce the value dss Veriust- ^ '$ ifftktora% h) in the mixing ■ f'femten of nickel zinc usd eenuge amounts of vanadium SjiiiiteaM "ö ^ ssizt vtetatn. The BE ^ PS 514023 er ^ wMfint ζ, β. Ferrites <kr BScJifiidsenden together- B ^ AS ^ rtefluiJg: '47 to 49 fe? Oiproz? At Fe ₂ O ₃ ,! 8.25 to W ^ '% ^f i ^f ^ i ^J A ¥ ^' P ^T J ⁱ ^ ^lni0 '& up to 22 mol percent ZnO,

Ferrites contain Mn cores for cell separation

itTnOTpmidBe ^ lieiaei ^ magneiisdiecSioS-, effect, such that the properties of the material on the whole not or hardly in an irreversible way under the influence of a strong magnetic equilibrium

fekks or a demagnetizing magnetic WcchielieWes be disturbed.

The ferrites according to the invention have a composition, expressed in metal oxide proportions, of 4S to 50 mole percent Fe ₂ O ₃ . preferably 49.2

2 _S to 493 mol percent, 22 to 49 mol percent NiO. 9 to 27 mole percent ZnO. 0.7 to U Moiorozent CoO and 0.1 to 0.5 mole percent V ₂ O ₉ .

The content of iron oxide Fe ₃ O ₃ must by no means be higher than 50 mol percent and even preferably

υ not higher than 493 percent oil. In addition, it should be noted that with a low value of the molar ratio NiO: ZnO a high content of iron oxide Fe ₂ O ₃ within the specified! Concentration range is favorable If, for example, the value

of the molar ratio NiO: ZnO approximately! to 3 is, the most favorable content of the iron oxide is about 49.4 to 49.9 mole percent. When the value is of the molar ratio NiO: ZnO is quite high, the content of the iron aoside is within the specified

new concentration area less critical,

Ute H'TsteüuBg der ERandungsgcmäScö materials corresponds broadly to that which is customary for the production of known nickel ferrites and nickel-zinc-ferrites. So you sinter at a temperature

temperature between 1000 and 14C) ⁹ C a mixture of compounds of iron, nickel, carbon, vanadium and possibly zinc (oxides of these metals and / or compounds which can be converted into the corresponding metal oxides at the sintering temperature),

so where these compounds wholly or partially by Ziivnr oehbildung Bfiaktionanrodukte of two or more of the metal oxides mentioned are replaceable. Table II mentions the values of the initial

lie of ^ - i.e. the quotient of the

, """Unü" der Anfenppermcßbjlftat, _v and

“· 'The des-temperature factor' of the initial permissibility for a number of materials! up to 14,> douche · ν misdi & Zusan3jnensetz, unsenjn: "of Table I are listed . ** '? * / ·'', *

The ele & tromagQ tables; Losses were always in the form of a magnet, around which a coil with an 'one free number of windings was placed ', with the loss of the 'coil body' occurring 'no correction was made' so that, sis are greater the VerlusiwsrtP listed in 'the board K as the eiagshülgigeg? Ferrite body

^ä zf ■? ■■ '

46808

Blackboard!

Sfateriar Mole percent
•. ·, ■■ ■ · .- =. ', NiO ZnO "- '■ · CoO , ■ ■ 50 ■ ■ " * Molye ^r rhiltn &·; 20 and ^: 20 and "FefOj - ■ ^ V ₂ O ₅ .. * - FMHJ . '£ a \ \ J 60 ⁰ C 55 "C 35.8 14.5 _. ·. . ί- ·. · ί. «... f · ■ '' 1 49.7 35.45 14.35 0.9 '2.5 2 49.3 35.3 14.3 0.9 2.5 3 49.3 35.3 14.3 0.9 0.20 2.5 4th 49.3 33.7 13.5 0.9 0.20 2.5 5 51.7 31.8 12.7 0.9 0.20 2.5 6th 54.4 22.8 26.1 1.2 0.20 2.5 7th 49.7 31.95 16.9 1.25 0.20 0.9 8th 49.7 30.0 19.3 1.25 0; 20 1.9 9 49.2 45.9 3.85 1.3 0.25 1.55 10 48.65 45.1 4.3 1.0 0.3 12th U 49.3 45.05 4.2 1.25 .0.3 10.5 12th 49.2 44.38 4.35 0.98 0.3 11th 13th 50.04 44.38 4.35 0.98 0.25 10 14th 50.04 0.25 IO Plate II Material //, let - at a? r Freqr-nz (in MHz) from F · ίΟ ⁶ in the Teni | ieTaturbereich -ft- - «* S IC 15 20 30 40 between 13 2 20 and 70 ° C

2 3 4th 5

£. O

IO

Ii

12th

71 73 79 73 70 50 295 102 63 24 23

P '

^ P

, 30

40

180 190 250 505 1170 200 790 +35 171 201 274 490 1140 251 323 578 + 14 52 63 97 195 575 230 279 3S5 + 13 58 67 88 120 202 240 290 450 63 70 88 105 135 252 280 a-7 105 138 270 490 43 190 +4 35 47 74 185 720 +5 79 91 105 115 132 238 200 200 210 230 140 173 205

+3
+73
+ 14
+ • 8

νί κ.

a ^ Materiai 1 is a mixed ferrite of nickel and ^ Zirtk ^ with a slight ^ iron deficit (i.e. with * an iron content which is lower than 50 mole percent 'Ρ) by :? in * this-material Ό, 9 mole percent fid häl d mil 2

: i |; ^ ejn;, ^ unte ^ rschiedlichep MeBfrequen2 £ n the total ^ enifej 'values of the material I- almost equal to ^^ y ^ .iü ^ ä ^ .i'TesjgertitoijMitoriF the ^ bifangs-M ^ ^^ bli ^^ JedöcSi-between 20 »and 7Ö ^{£ |} C deuts ^ | iicpi) longer, that is, better. If the material 2 - ^^ i || ri | ig ^ * _l | eBge ^ O;? Wt .-%> V2Qi is ^given; * | dpi: a! s; s01clies-or in the form of ammonium vanadate, ,, Bntvved ^ fdein Ausgafigsgernisch or the ground νοί ^ ιηΐέϊϊέπ product is added, the -received, desssr. -isa yorSisgendsn related important magnetic properties are all clear, better, are; ^ as the corresponding own;

<; 5 shafts des.jjvfateriais.1. . ·, .. · ^! _: . ^

In order to show that the resistance to "magnetic impact" is closely related to the selected iron content, three different materials were produced whose molar ratio NiO: ZnO, as well as the CoO content and the V ₂ O ₅ -GeHaH _{5, were} always the same. however

two of the three materials had an iron content higher than 50 mole percent Fe ₂ O ₃ .

The three relevant materials were each

Influence of a constant magnetic field mi <one Strength four times the coercive force of the relevant Material exposed. There were magnetic cores that were as little as possible before magnetization

had different loss values, compared with each other.

The "magnetic shock effect" was obtained by using the relevant magnetic cores for 5 min. have long been exposed to the influence of a constant magnetic field of 20 Oe.

Table III shows the influence of the "magnetic

Plate III

material

tgfl

10 ⁶ with an i— r \. ■; nz (in MKz) of impact effect on materials 4, 5 and fi, material 4 has the same chemical approval position as material 3, (which, however, was not produced using a somewhat different process , while, as from Table I shows that the risk content of materials 5 and 6 is higher than 15% mol% Fe ₂ O ₃ .

73 2 after Stei 10 after Stei 20th after Stei 70 before ar .nagne- rune before the magne excitement before the magnetic excitement 50 magne tables in % magne tables in % magne ting in % tables Push tables Push tables ÄO0- Shock treat Push treatment Push treatment ohand- lung treatment treatment iung 58 0 91 3 229 13th 4th 58 82 30th 88 124 41 202 529 292 5 63 Π4 31 88 140 33 135 286 107 6th 87 105 138

As can be seen from Table III, the loss factors of materials 5 and 6 are very sensitive against the magnetic shock, while those of the material 4 are hardly influenced thereby. the Insensitivity to magnetic shock effects due to the selected iron content is retained, if the ratio NiO: ZnO is allowed to change.

See e.g. B. Table IV below for material 7 of Table I (NiO: ZnO = 0.9), which takes 10 min long exposure to a permanent magnetic field of 12 Oe.

Plate IV

ι-

10 ". At

Before the

magnetic

Sioß treatment

1.5 MHz
2MHz

40

43

After

magnetic

Shock treatment

42.5 45

These figures show that material 7 is also very resistant to "magnetic impact". The same applies to material 8 of the Tsfc! ί (NiG: ZnG = 1.9), as it turns out from the following table V, which relates to the manner; how this material reacts to a magnetic shock treatment carried out for 10 minutes by means of a constant magnetic field of 25 Oe. ^: ' ■ -'<* ■ '

Plate V

Before the

Mä'rriefiscnen

Shock treatment

After

magnetic

Sioß treatment

ίΟΛνΙΗζ
IiSMHz

! 85

38

46

71

160

Similar results are seen with materials with a fairly high molar ratio NiO: ZnO obtained.

Table VI below relates to material 11 of Table I, with a molar ratio NiO: ZnO of 10.5, the material being exposed to a constant magnetic field of 35 Oe for 10 minutes will.

Plate VI

tgA

10 ^ft . at

Before the

magnetic

Slush treatment

After

magnetic

Shock treatment

30MHz
40MHz
50MHz

230
279
385

225
295
392

The lower limit of the iron content is determined by the flow of this content on the temperature factor. Thus, the material has 9 of Table I (Fe ₂ O ₃ = 49.2 mole percent) of a temperature factor F Her Anfangspermeabiiität of 73 · 10 ^-6 between 20 and 55 ⁰ C. This is a material with a molar ratio of NiO: ZnO of 1.55, which is a fairly low value. For a fairly high value of the molar ratio NiO: ZnO, as already mentioned, the iron content is less critical. For example, the materials 10, 1ί and 12 de>"Tafel! (With a molar ratio NiO: ZnO = 10.5 to 12) are all of good quality according to the standards applied in this context, although that in mol% Fe ₂ O ₃ The iron content expressed varies between 48.6 and 49.3. In addition, it should be mentioned that in the case of material 12, in order to maintain a temperature factor F of approximately 0 between 20 and 60 ^° C., the sign of the difference quotient -j '' is exceptionally changed in this temperature range Have to take it into account

= 55 ... Lt-j. .. i ^ - ^ üwaiwiija *; ·, ..

lcizunwn: ^ icht | (^ dnandepä ^ eichen | M '"

JlJ ^ j ₁ -. ,.

■> not lower Bt «Is about 0.8) y. !

The foata-related 13 and 14 of the table! have, as well as the aforementioned materials 5 and 6 of these Tafel, an iron content greater than 50 mole percent FeiQ. Although their chemical composition κ

Plate VI

from each other atracH-NciI inter alia jcuuvu wvmv himi Uuh ischuß contain iron (that is, a _'f iron content greater than 50 mole percent Fe ₂ O _3), they are also both significantly sensitive to magnetic shock effect, as can be seen from the following table VLI.

material

20th 30th

Ig *

l'l

iffbä a frequency (in MHz) of

30th

before the
magnetic
SIoO treatment

after
magnetic S1O0 treatment

252 270

280 375

In conclusion, it should be noted that nickel (zinc) KobaH vanadium ferrites have been described in British patent specification 911,795. However, these known ferrites all contain an excess
in %

40

before the
magnetic
Material processing

280 490

after the magnetic shock treatment

361

845

Increase i%

29

72

too much iron, to such an extent that the _{iron content, expressed in mole percent Fe 2} O ₃ , is even higher than 50.5.

»« • / 3 ·

Claims (1)

1646J08 * .- ■. zm * SRd ¹ ^ Claim: IUr MftfC £ tkeme for use formators in FerMehgerätcit iZeflenaWeokfreijUenz