Ba-ferrite thin film rigid disk for high density perpendicular magnetic recording

Morisako, Akimitsu; Matsumoto, Mitsuhiro; Naoe, M.

doi:10.1109/tmag.1986.1064350

Cited by 80 publications

(21 citation statements)

References 3 publications

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“…The squareness is the ratio of remanence to the magnetization in the field of 10 kOe. The Sperpof the films prepared at Ts of 550°C were between 0.65 and 0.75, while those prepared at Ts of 600°C were about 0.6 less dependence on P0 2 in the in-plane direction (Spara) and Poz . At Ts of 550 QC, the Sparaas well as Sperpwas higher than that at Ts of 600 QC.…”

Section: ~~-L~-'2~0~--l-~-4~o~mentioning

confidence: 91%

Effect of Partial Oxygen Pressure on Magnetic Properties of Strontium Ferrite Thin Films

1998

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Abstract~Strolltiurn hexagonal ferrite (SrM) thin films were prepared with a dc magnetron sputtering system,and the crystal structure and magnetic properties were studied. It was found that structural and magnetic properties of the films prepared at the substrate temperature (Ts) of 600"0 were affected by partial oxygen pressure (P02 ) as compared with those of the fihn prepared at Ts of 550"0. The coercivity of each film prepared at Ts of 550"0 was about 5kOe in the pel'pendicular direction, although that of the films prepared at the Ts of 600°0 and P02 of 10% was about 2kOe with preferentiai orientation of c-axis was observed. The grain size of the films prepared at the Ts of 600"0 was larger than that of other films. It co'tlld be considered that growth of the grains lead to the decrease of the coerdvity. IN'l'aODUCTloNStront,ium hexagonal ferrite (SrM) thin films with the magnetoplumbite type (M~type) crystal structure as well as barium ferrite (DaM) thin films are expected to be high density recording media because of their chemical stability, mecbanical hardness, and moderate hard magnetic properties [11-(21. It is possible to use hexagonal ferrite films a.<; longitudinal and perpendicular recording media in the next generation by shifting tbe c-axis orientation. It is reported tbat SrM has higher coercivity than that of DaM [3]-[5], Therefore we have attempted to modify the SrM film to the properties suitable for the recording medium 1 • The SrM thin films were prepared at various partial oxygen pressure (P02 ), and their crystal structure and magnetic properties were studied. rI, EXPERIMENTALThe SrM films Were prepared with a dc magnetron sputtering system. A sintered ferrite disk with the stoichiometric composition of M~type, i.e. Sr:Fe = 1:12, was used as the target. The substrate temperature (Ts) was 550 and 600 <>C. Thermally oxidized silicon wafers were used as the substrate and the thickness of the films were about 1500 A. The films were prepared at the total gas pressure of 2 mTorrand the partial oxygen pressure (POll ) was varied from 0 to 40 %.Ill. RESULTS AND DISCUSSfON Fig.1 shows X-ray diffraction (XRD) diagrams for the films prepared at Ts of 600°C. The lines of SrM phase were observed on eaeh diagran~ when the P02 was 10%. The most of lines were predominantly from e-plaue of hexagonal structure when the P0 2 was 10%. 'However when the Poz was higher than 10%, the orientation of the films were random. So tl1a,t it was considered that 4:00. high P02 disturbed the orientation of the films at Ts of 600°C. Tbe films prepared at Ts of 550 <>C became random orientation. It was because that the Ts was not enough to orient the films to thee-plane. . Fig.2 shows the surface structure of the films prepared at various Po z observed with SEM. The grains of the film prepared at Ts of 550°C looks like needle or chunk. The grain size were about 500 A audit was -194-

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Section: ~~-L~-'2~0~--l-~-4~o~mentioning

confidence: 91%

Effect of Partial Oxygen Pressure on Magnetic Properties of Strontium Ferrite Thin Films

1998

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“…The authors have been studying a magnetoplumbite type of hexagonal Ba-ferrite(BaM) thin films prepared by sputtering [5] and sol-gel method [6] and reported that Ba~ sputtered rigid disks with small c-axis dispersion angle Ll e so possess an excellent recording characteristics [7]. According to their reports, the recording density Dso depends on Ll e 50 and the smaller Ll e so results in the higher Dso.…”

Section: Infroductionmentioning

confidence: 99%

The Effects of Ph Addition on Crystal Structure and Magnetic Properties of Ba-Ferrite Sputtered Films

1994

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Abstract---Pb added Ba-ferrite films were prepared at the substrate temperature of 550 CC by dc magnetron sputtering and their crystallographic characteristics and magnetic properties were investigated. The addition of Pb facilitates the crystallization and improves the crystallinity for hexagonal M phase. The films prepared in this study exhibit a good c-axis orientation and the c-axis dispersion angle L1 (lso is as small as 1°. The coercivities Hc.L and Hc H and Ms of the films are 1.0 kOe, 0.2 kOe and 240 emu/cc, respectively.

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“…M-type barium ferrite (BaM) thin films are candidates in MicroElectro-Mechanic Systems and magnetic recording media [1,2]. Recently they were proposed to be the key materials for thin film non-reciprocal microwave devices [3].…”

Section: Introductionmentioning

confidence: 99%

Barium ferrite thin films with faceted grains fabricated by using ethylenediaminetetraacetic acid

Zhang

Zhou

et al. 2011

Journal of Alloys and Compounds

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Ba-ferrite thin film rigid disk for high density perpendicular magnetic recording

Cited by 80 publications

References 3 publications

Effect of Partial Oxygen Pressure on Magnetic Properties of Strontium Ferrite Thin Films

Effect of Partial Oxygen Pressure on Magnetic Properties of Strontium Ferrite Thin Films

The Effects of Ph Addition on Crystal Structure and Magnetic Properties of Ba-Ferrite Sputtered Films

Barium ferrite thin films with faceted grains fabricated by using ethylenediaminetetraacetic acid

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