Mn
A manganese carbide (Mn 4 C) magnetic material and a production method therefor are provided. According to one embodiment, the saturation magnetization of the Mn 4 C magnetic material increases with increasing temperature, and thus the Mn 4 C magnetic material is applicable to fields in which thermally induced magnetization reduction is critical.
1. A Mn 4 C magnetic material showing diffraction peaks of (111), (200), (220), (311) and (222) crystal planes at 2θ values of 40°, 48°, 69°, 82° and 88°, respectively, in an XRD analysis.
2. The Mn 4 C magnetic material of claim 1 , wherein the diffraction peak intensity at 2θ values of 43° and 44°, which correspond to impurities, is equal to or less than 2.5% of the diffraction peak intensity of the (111) crystal plane in the XRD analysis.
3. The Mn 4 C magnetic material of claim 1 , wherein magnetization of the Mn 4 C magnetic material starts to increase in a temperature range of 30 K to 80 K, and the increased magnetization thereof is maintained in a temperature range of 540 K to 640 K.
4. A method for producing the Mn 4 C magnetic material according to claim 1 , the method comprising:
melting a mixture of manganese and carbon-based compound to obtain a metal mixture;
cooling the melted mixture to produce an alloy ingot; and
crushing the alloy ingot, and then removing impurities by magnetic separation.
5. The method of claim 4 , wherein the carbon-based compound is one or more selected from graphite, graphene, carbon nanotubes, and carbon fibers.
6. The method of claim 4 , wherein the mixture of manganese and carbon-based compound comprises 93 to 97 wt % of manganese and 3 to 7 wt % of the carbon-based compound.
7. The method of claim 4 , wherein the melting is performed by a plasma arc melting method.
8. The method of claim 4 , wherein the melting is performed at a temperature of 1,500 to 2,500 K under an inert atmosphere.
9. The method of claim 4 , wherein the cooling comprises the cooling the melted mixture to a temperature of 200 K to 300 K at a rate of 10 2 K/min to 10 5 K/min.
10. A method for producing the Mn 4 C magnetic material according to claim 2 , the method comprising:
melting a mixture of manganese and carbon-based compound to obtain a metal mixture;
cooling the melted mixture to produce an alloy ingot; and
crushing the alloy ingot, and then removing impurities by magnetic separation.
11. A method for producing the Mn 4 C magnetic material according to claim 3 , the method comprising:
melting a mixture of manganese and carbon-based compound to obtain a metal mixture;
cooling the melted mixture to produce an alloy ingot; and
crushing the alloy ingot, and then removing impurities by magnetic separation.