MAGNETIC DISK SUBSTRATE, METHOD FOR MANUFACTURING THE SAME, AND MAGNETIC DISK

• Main Authors: HATAKEYAMA HIDEYUKI, YONEMITSU MAKOTO, FUJII YASUO, KITAWAKI KOTARO, MURATA TAKUYA, SAKAMOTO RYO, TODA SADAYUKI
• Format: Patent
• Language: English; Japanese
• Published: 19.09.2019
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; METALLURGY; PHYSICS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide a magnetic disk substrate in which defects generated in a surface of an underlying plating layer made of an electroless plating can be efficiently reduced and the fluttering characteristics are improved, a method for manufacturing the magnetic disk substrate, and the magnetic disk.SOLUTION: The magnetic disk substrate according to the present invention includes: an aluminum alloy substrate; and an underlying layer formed in the surface of the aluminum alloy substrate. In the glow discharge emission spectral analysis in the depth direction from the surface of the magnetic disk substrate, the maximum value (I(1)) of the intensity of the light emission of Fe in a specific boundary region (D(1)) of the boundary region formed between the underlying plating layer and the aluminum alloy substrate where the intensity of the light emission of Al in the aluminum alloy substrate is 50% to 84% of the average value of the light emission of Al is larger than the average value (I(1)) of the intensity of the light emission in the aluminum alloy substrate.SELECTED DRAWING: Figure 1 【課題】フラッタリング特性を向上すると共に、無電解めっきで形成した下地めっき層の表面に発生する欠陥を有効に低減した磁気ディスク基板及びその製造方法並びに磁気ディスクを提供する。【解決手段】本発明の磁気ディスク基板は、アルミニウム合金基板と、前記アルミニウム合金基板の表面に形成された下地めっき層とを備え、前記磁気ディスク基板の表面から深さ方向へのグロー放電発光分光分析において、前記下地めっき層と前記アルミニウム合金基板との間に形成される境界領域のうち、前記アルミニウム合金基板の内部におけるＡｌの発光強度の平均値の５０〜８４％である特定境界領域（Ｄ（１）Ｉ（５０−８４））でのＦｅの発光強度の最大値（Ｉ（１）Ｆｅ（ｍａｘ））が、前記アルミニウム合金基板の内部でのＦｅの発光強度の平均値（Ｉ（１）Ｆｅ（ａｖｅ））よりも大きい。【選択図】図１