Magnetic head and magnetic recording device

A magnetic head, comprising:

• a reproducing section,
• the reproducing section including:
• a first shield,
• a second shield,
• a third shield,
• a fourth shield, and
• a stacked body,
• the third shield and the fourth shield being between the first shield and the second shield,
• a second direction from the third shield to the fourth shield crossing a first direction from the first shield to the second shield,
• the third shield including:
• a first shield portion,
• a first opposing shield portion between the first shield portion and the second shield in the first direction, and
• a first shield intermediate layer between the first shield portion and the first opposing shield portion;
• the fourth shield including:
• a second shield portion,
• a second opposing shield portion between the second shield portion and the second shield in the first direction, and
• a second shield intermediate layer between the second shield portion and the second opposing shield portion,
• the stacked body including:
• a first magnetic layer,
• a second magnetic layer between the first magnetic layer and the second shield in the first direction,
• a third magnetic layer between the first shield and the first magnetic layer in the first direction,
• a fourth magnetic layer overlapping at least a part of the third magnetic layer in the first direction,
• a first intermediate layer between the first magnetic layer and the second magnetic layer, and
• a second intermediate layer between the second magnetic layer and the second shield,
• the fourth magnetic layer including Mn,
• the first intermediate layer including at least one selected from the group consisting of Ru, Ir, Os, Re and Rh, and
• a first intermediate layer thickness of the first intermediate layer in the first direction being not less than 0.3 nm and not more than 0.5 nm, or not less than 0.7 nm and less than 1.0 nm,
• the second intermediate layer being non-magnetic and conductive,
• the second intermediate layer being in contact with the second magnetic layer and the second shield,
• at least a part of the first magnetic layer being in contact with the second magnetic layer and the second shield,
• at least a part of the first magnetic layer being between the first shield portion and the second shield portion in the second direction,
• at least a part of the second magnetic layer being between the first opposing shield portion and the second opposing shield portion in the second direction,
• a ratio of a first magnetic thickness of the first magnetic layer to a second magnetic thickness of the second magnetic layer being not more than 0.67 or not less than 1.5,
• the first magnetic thickness being a first product of a first thickness of the first magnetic layer in the first direction and a first saturation magnetization of the first magnetic layer,
• the second magnetic thickness is a second product of a second thickness of the second magnetic layer in the first direction and a second saturation magnetization of the second magnetic layer.