DE1953286B2 - FERRITE - Google Patents

Description

The invention is therefore based on the fact that it was established, and also a sintered body was made higher, that SnO ₂ and Li ₂ O as additives used at the same time as density with large and uniform crystalline particles down the ferritic properties and the smallest possible pores and crevices to visibly generate the magnetic losses most effectively, as this can improve on the one in question, and that CaO and SiO _{2 are known} as additives in the field (J. Appl. Phys. Vol. 35 [1964], together with SnO ₂ and Li ₂ O for the production p. 1646; Siemens Electronic Component Bull. Vol. 1 of ferrites from manganese and zinc oxide especially [1966], p. 138; J. Phys. Soc. Japan Vol. 11 [1963], have a beneficial effect.

P. 684). A basic composition of 55. Before describing the invention in more detail using a few mole percent MnO and Fe ₂ O ₃ and 25 or using examples, it should be noted that 11 mole percent ZnO is suggested. Also, Example 1, a considerable improvement in the quality sintering at a high temperature (over 1250 ⁰ C) factor and the Hystereseverlustfaktors occurs, if provided, and small amounts of additives. a tin compound and a lithium compound Both of the purposes of increasing the size 60 of a manganese-zinc ferrite having a basic composition of crystal particles and producing a sintered composition of 55.9 mole percent Fe ₂ O ₃ , 38.0 mole percent high density solid. MnO and 6.1 mole percent ZnO as main components

The additives are added to add to the waxing so that the additives eventually promote that of the crystal particles. Take this measure in the form of SnO ₂ and LiO ₂ ,
is mainly danr into effect, when the body 65 from the examples 2 to 6 show that the effect of sintering at a high temperature over 1200 ⁰ C a mixture of SnO ₂ and Li ₂ O as is. If relatively large amounts of additives are essentially used in the case of manganese-zinc-ferrites, the permeability decreases, and the loan remains unchanged from that in example!

The basic composition mentioned varies from 36.0 mol percent MnO to 8.8 mol percent

Have basic compositions, and that opti has ZnO and 55.2 mole percent Fe ₂ O ₈ . It k ⁰ ™haben

Fine amounts of additives and permissible limits due to excellent magnetic oxide materials

for this purpose, for each recommended ferrite composition, the addition of 0.6 to 2.7 percent by weight of SnU ₄ and

stand. S 0.01 to 0.1 percent by weight Li ₂ O can be obtained.

From Example 7 it can be seen that the effect of the two conditions tan δ / μ <1.0 x 10 and

of SnO ₈ and Li ₈ O, which at the same time meet AlO <3 in the ferrite. Such excellent ^m ^ ß ^

Composition exist, even then table properties could not be changed by any of the previously

emerges when a special treatment, such as B. known processes are implemented,

a heat treatment to improve the magne- io assist> iel3

table properties is carried out. _,

From Example 8 it can be seen that the effect The F i g. 5 and 6 show the effect of another Gedes addition of SnO _e and Ii ₈ O itself in a substantial mixture of Ii ₂ O and SnO ₈ , which remains unchanged in a manganese, even if a further additional zinc-ferrite is added, which is a basic mixture CaO and SiO ₂ in different proportions of 36.0 mol percent MnO, 9.5 mol percent amounts of the manganese-zinc composition InO and 54.5 mol percent Fe ₈ O ₈ . From these is included. Diagrams show that excellent magnetic

The samples that were used in the examples were oxidized by exposure to SnO ₂

were in accordance with the known and Li ₂ O in areas of

Ferrite sinter manufacturing process manufactured. ao _ "". ,. _t ^ -cr »<ri-> ronArhtz

In particular, were iron oxide, Mangankarbo- ² '° ϊ percent by weight SnO ₂ 3.2 wt ύ

nat, zinc oxide, calcium oxide and silicon oxide ^{add, porzen}

together with the essential additives according to ^un weight percent <Li, 0 g 0.06 weight

of the invention, ie tin oxide and lithium carbonate '" ^μ ~

individually weighed to a predetermined percentage

to receive settlement; these ingredients were obtained that meet the two conditions mixes and tan <5 / μ <in a ball mill for 60 hours 1.0 ■ 10- «and Λ10 <3 ground at Ί00 kHz, with alcohol filling as a dispersant.

was used; then the mixture was used for 4 hours

the long ^{pre-sintered at 800 0} C, into the desired 30

Pressed form; 8 hours at 118O ⁰ C in a 0.4 ° / ₀ FIGS. 7 and 8 show the effect of a nitrogen atmosphere containing Ge oxygen, heated mixture of Li ₂ O and SnO ₂ , which is a manganese-zinc and then cooled. During the cooling process, the ferrite was added, which controlled a basic oxygen content in the nitrogen atmosphere. Settlement of 34.0 mole percent MnO, 11.60 mole percent

All samples in Examples 1 through 7 contained 35 ZnO and 54.4 mole percent Fe ₂ O ₃ . From these

0.06 parts by weight ozent calcium oxide and 0.02 Ge diagrams shows that the loss factors of the

weight percent silicon oxide, although this is not in ferrites due to the addition of SnO ₂ and Li ₂ O in

is mentioned in each case. Areas of

In Figures 1 through 18 of the drawings, the "" ^., I ^ er ^^ ~> ir * - ,. κ * ,.

r ^ .jj c_c j TJ j α »-ι. 0 8 wt., Percent < SnO ₄ ^ 2.3 wt.

Subject of the invention on the basis of execution 4 ° 'v ^ w ^ i ..., ^^ _ ₂ _,

Examples are shown and explained in more detail below. percent

B is ρ ie 1 1 0 percent by weight <LiO ₂ ^ 0.07 weight

The F i g. 1 and 2 show that the effect of a percent

Mixture of Li ₂ O and SnO ₂ , which can be significantly improved to a manganese 45 and that from

Zinc ferrite is added, which contains a basic set of magnetic oxide materials drawn

Settlement of 38.0 mol percent MnO, 6.10 mol percent can be achieved in the two conditions tan / μ <

ZnO and 55.90 mol percent Fe ₂ O ₃ , which meet the loss of 1.2 · 10- ^e and / ilO <4 at 100 kHz. Of the-

Factors tano / μ and Λ10 improved excellently. like loss factors could not be caused by any of the

It is easy to see from the diagrams that such known methods are being implemented.

tano / μ and / ilO by adding SnO ₂ and. -ic

Li ₂ O in amounts in the range of ^Example

., _ _ _. The F i g. 9 and 10 show the effect of a Ge-0.6 Gewicntsprozent S SnO ₂ S 2.7 weight _{m S} j ches of SnO ₂ nd i-Li ₂ O, the p a manganese-zinc percent _{55 err} j _t is added, the a basic

^and _n _. , _T. , _ _N. _. . Settlement of 34.0 mole percent MnO, 10.75 mole percent

0 percent by weight <Li ₂ O s 0.1 percent by weight _{ZnQ and 5525 Mo} i _{percent Fe?} o owns _3.

percent _From J ₁ J _656n diagrams it can be seen that

noticeably improved. Excellent excellent magnetic oxide materials can be obtained by materials which have the two additions of SnO ₂ and Li ₂ O in ranges of

conditions tan <5 / μ <1.0 · 10 " ^β and Λ10 <3 at. _. _Ut ." _ . _Λ . ".,.

100 kHz, which has not yet been achieved ° Percentage by weight <SnO ₂ g 1.4% by weight

could. . ^Percent

and

Example2 0 weight percent <Li ₂ O g 0.06 weight

The F i g. 3 and 4 show the effect of a percentage

Mixture of Li ₂ O and SnO ₂ , which is a manganese can be obtained that meets the two conditions

Zinc ferrite is added, which meet a basic composition ίζηδ'μ < 1.2 ■ ¹ O " ⁶ and Λ10 <4. This

Loss factors could not be realized by any of the known methods.

Example 6

The F i g. 11 and 12 show the effect of a mixture of SnO ₂ and Li ₂ O, which is added to a manganese-zinc ferrite, which has a basic composition of 32.0 mol percent MnO, 13.15 mol percent ZnO and 54.85 mol percent Fe ₁ O ₉ owns. As can be seen from the diagrams, excellent magnetic oxide materials can be produced by adding SnO ₁ and Li ₁ O in the range of

0.4 percent by weight ^ SnO ₁ g 1.1 percent by weight

Li ₁ O έ 0.05 weight

0.01 percent by weight

percent

can be obtained that satisfy the two conditions tano / μ <1.3 · 10- «and AlO <5 at 100 kHz.

The result of many among various other than those mentioned in the preceding examples sintering conditions - that is, at an 8-hour sintering at 118o ⁰ C in a 0.4 ° / ₀ oxygen-containing atmosphere of nitrogen - was found that the effect of a mixture of tin oxide and lithium oxide are obviously observed although the optimum composition ratios of SnO ₂ and Li ₂ O were little changed.

The effect of the addition of SnO ₂ and Li ₂ O was essentially unaffected even if the sintered body was subjected to a heat treatment in order to improve its magnetic properties.

An example for this case is shown in Example 7 below.

Example 7

13 and 14 show the loss factors tano / μ and AlO of samples of a ferrite which has the same composition as in Example 1, ie MnO: ZnO: Fe ₁ O ₃ = 38: 6.1: 55.9 mol percent , and which contains Li ₁ O and SnO ₁ as additives; The samples were prepared according to the sintering by being subjected to a heat treatment at 25O ⁰ 32stündigen C.

These diagrams show a considerable improvement in the loss factors tan ί / μ and AlO due to the addition of SaO ₂ and Li ₂ O in areas tan% <0.8 · 10- »and AlO <3 at 100 kHz.

The manganese-zinc ferrites used in this example contained, in addition to SnO ₂ and Li ₂ O, 0.06 percent by weight CaO and 0.02 percent by weight SiO ₂ . The effect of the mixture of SnO ₂ and Li ₂ O itself remained essentially unaffected when the added amounts of CaO and SiO _{2 were} changed, as can be seen from Example 8 below.

Example 8

The F i g. 15 and 16 show diagrams of tano / μ and AlO of manganese-zinc ferrites, which have a basic composition of 38.0 mol percent MnO, 6.1 mol percent ZnO and 55.9 mol percent Fe ₁ O ₃ , and 0 to 0.3 Contain percent by weight CaO and 0 to 0.04 percent by weight SiO _2. In contrast to this, FIGS. 17 and 18 show diagrams of tand / μ and AlO of these ferrites which contained 0.05 percent by weight Li ₁ O and 1.5 percent by weight SnO ₁ as a further additive mixture.

A comparison of these diagrams shows that the effect of the addition of SnO ₁ and Li ₂ O per se is still clear in the case of the simultaneous presence of an additional mixture of CaO and SiO ₂ in various amounts.

Each of the preceding examples shows that the addition of a mixture of SnO ₂ and Li ₂ O is very effective in improving the loss factors of manganese-zinc ferrites.

Experiments were also carried out to determine the actual limits on the amounts of SnO ₂ and Li ₁ O added, using samples of many Mn-Zn ferrite compositions other than those given in these examples, which expand over a period of time specified area extended:

28 mole percent S MnO
51 mole percent <Fe ₂ O ₉
Remainder ZnO.

40 mole percent; 58 mole percent;

from

SnO ₁ ύ 2.9 weight and

1.0 percent by weight
percent

O <Li ₁ O ύ 0.08 percent by weight

Thus, excellent magnetic materials can be obtained which meet the two conditions. As a result of the addition of SnO ₂ and Li ₂ O, the same effect observed in each manganese-zinc-ferrite composition could be obtained. As a criterion for

a noticeable improvement in the magnetic properties can be stated as a reduction in the values of tano / μ and AlO to less than 1.3-10- · or. The effective amounts of SoO ₁ and Li ₁ O added to this. Match criterion, lay

at less than 3.2 percent by weight or 0.125 percent by weight.

It has been found experimentally that the improvement in the loss factors, which corresponds to this criterion, with an addition of SnO ₁ and Li ₁ O in the

55 cases where the crowd is hard to come by MnO contained in the ferrite composition is considerably lower than the above-mentioned MnO limit is.

In addition 6 sheets of drawings

- ^ ss * ·

2757

Claims (4)

The urostructure of the sintered body is adversely affected by the claims: The additives are therefore only effective in a very small amount. π 1. Ferrite made of manganese and zinc oryde with low- The invention, however, is based on the object like to create good tactor (tan ί / μ) and low hysteresis 5 ferrites with low losses, which in Loss factor (MO), consisting essentially of a filter in a frequency range of approximately 28 to 40 mole percent MnO, 51 to 58 mole percent 100 kHz can be used. The invention : Λ also _v Fe ₈ Oj and remainder ZnO, marked on the reduction of the quality factor rad of the _z directed by a part of 0.4 to 3.2 weight hysteresis loss factor. For this purpose percent SnO ₁ and 0.01 to 0.125 weight percent io it is important to have a corresponding basic composition Ii ₈ O. Settlement to be selected, ie an MnO content of 2. Ferrite according to claim 1 and with a quali- about. To provide 30 mole percent or more in order to increase the efficiency factor of less than 1.3 · 10- · and a specific resistance between the particles of a ₍ hysteresis loss case of less than 5, marked sintered body, and additives ajiszu-, characterized by a proportion Select from 32.0 to 38 * 0 mol- 15 , which are suitable for influencing the valency percent MnO and 54.4 to 55.9 mol percent Fe, O ₃ . 3. Ferrite according to claim 1 or 2, characterized in that the invention is based on a proportion of less than 0.3 weight task by 0.4 to 3.2 weight percent SnO ₂ and percent CaO and less than 0.04 weight percent 0.01 to 0.125 percent by weight Li ₂ O. SiO ₂ . 20 To increase the resistance between the particles 4. Increase ferrite of manganese and zinc oxide with the size of the crystal particles in the quality factor of less than 1.2 x 10 ^-6 and a sintered body must be elative small, ie 5 to Hystereseverlustfaktor of less than 5, comprising 8 microns be. This is less than one tenth of essentially 36 to 38 mole percent MnO, the size of high permeability ferites. 54.5 to 55.9 mole percent Fe ₂ O ₃ and the rest of ZnO, Ge 25 For this reason, in Skitertemperatur is characterized by a proportion of 0.6 to the preparation of ferrite erfindungsgemäJen less 3.0 percent by weight SnO _2, 0, 01 to 0.1 percent by weight than 1200 ⁰ C, since at this temperature the growth percent Li ₂ O, O ₁ Uj to 0.12 percent by weight CaO of the crystal particles is lower. and 0.015 to 0.025 percent by weight SiO ". In the ferrite according to the invention, SnO _{2 form} 30 and Li ₂ O form a solid solution with the ferrite and influence the valency of the ions, in particular of the Fft ²⁺ ions, so that the properties with regard to en: · Magnetic losses of ferrite are improved. The addition of these additives does not serve The invention relates to a ferrite made of manganese and increasing the particle size, which should be avoided especially in the case of zinc oxide with a low quality factor (tano / μ) and the production of ferrites with low losses and a low hysteresis loss factor (Λ10). The amount of Fe ^a + ions essentially 28 to 40 mol percent MnO, 51 bis influences the eddy current losses of the ferrites. Since 58 mole percent Fe ₈ O ₃ and the remainder ZnO. the eddy current losses represent a high percentage of the From British patent specification 1071611 a 40 total losses are shown, their reduction is for Process for the production of ferrites from manganese. Production of a ferrite with low losses and zinc oxide known, which is essential to the achievement. a high magnetic permeability and to keep the particle size small and the directs high magnetic flux density. To increase this resistance between the particles Z ^'1, purpose, it is essential to have a special ground state 45 may CaO and SiO ₂ as additives used to select composition of the ferrites, ie a.