Wondering if anyone can give me a clue as to where I might look for information on what the best core material would be for an electromagnet if price were not an issue. I need as much magnetic strength as possible for between 3-9 volts DC. At between 80-160Hz. Basically this is a solenoid that moves an armature bar attached to a spring. Corrosion is not an issue. Price is not an issue. Only efficiency. Soft iron is usually the first choice but I'm looking for something at the top end of performance. Thanks If there is a better forum to ask this question under please let me know.