Corrosion study in TbFeCoCr amorphous magneto-optical films

Author

Kobayashi, H. ; Ogino, K. ; Takayama, S.

Author_Institution

IBM Japan, Kanagawa, Japan

Volume

26

Issue

5

fYear

1990

fDate

9/1/1990 12:00:00 AM

Firstpage

1361

Lastpage

1363

Abstract

(Tb₂₀Fe₆₅Co₁₅)₉₄Cr ₆ film shows high corrosion resistance with good magnetooptical properties, H_c=4.9 kOe, θ_k=0.3°, K_u=1.4×10⁶ erg/cm³ and T_c=230°C. Pit corrosion in 1N-NaCl aqueous solution and wet corrosion in 85°C and 85%RH atmosphere were studied for TbFeCo films with and without Cr addition. It is suggested that pit corrosion occurs by a chemical reaction between the anodic pit wall and the cathodic film surface, resulting in a piling up of corroded products inside the pits. On the other hand, wet corrosion in TbFeCo and TbFeCoCr films shows a bubble-chain-like morphology similar to conventional filiform corrosion observed in a coated film. This seems to take place by discontinuous movement of the anodic reaction area ahead of the bubbles

Keywords

chromium alloys; cobalt alloys; corrosion; ferromagnetic properties of substances; iron alloys; magnetic properties of amorphous substances; magnetic thin films; magneto-optical effects; terbium alloys; (Tb₂₀Fe₆₅Co₁₅)₉₄Cr ₆; 230 degC; 85 degC; NaCl; TbFeCo films; TbFeCoCr; amorphous magneto-optical films; anodic pit wall; bubble-chain-like morphology; cathodic film surface; chemical reaction; corroded products; filiform corrosion; high corrosion resistance; magnetooptical properties; pit corrosion; wet corrosion; Amorphous magnetic materials; Amorphous materials; Atmosphere; Chromium; Corrosion; Magnetic anisotropy; Magnetic films; Magnetic properties; Perpendicular magnetic anisotropy; Plasma measurements;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.104376

Filename

104376