====Samarium Cobalt Magnet Properties====
Sintered SmCo properties defined in FEMM are meant to be representative of typical examples rather than strictly based on the products from one vendor. Reasonable references are the Wikipedia [[https://en.wikipedia.org/wiki/Samarium%E2%80%93cobalt_magnet|SmCo]] page and [[https://web.archive.org/web/20201218013444/https://www.buntingeurope.com/wp-content/uploads/2018/07/BME_Samarium_Cobalt_data_sheet.pdf|https://www.buntingeurope.com/wp-content/uploads/2018/07/BME_Samarium_Cobalt_data_sheet.pdf]].
SmCo magnets come in two formulations:
* //SmCo1:5// was the first developed SmCo alloy. Energy products for this alloy range from 16 to 25 MGOe. This alloy has a high electrical conductivity with 20 MS/m being a representative value. Based on manufacturer's specs, a relative permeability 1.03 is typical for this alloy.
* //SmCo2:17// is a more recent SmCo alloy. Energy products for this alloy are higher, ranging from 20 to 35 MGOe. Electrical conductivity is lower with 1.16 MS/m being a representative value. Based on manufacturer's specs, a relative permeability 1.1 is typical for this alloy.
Both alloys have a very high coercivity and a straight-line second-quadrant demagnetization curve.
On the basis of data from many vendors, the numerical designation of the magnet grade represents the best-case energy product in units of MGOe as measured at room temperature (20°C) for a range of energy product usually spanning a range of 2 MGOe. However, magnets are rarely delivered magnetized to this best-case magnetization. For this reason, it is assumed that the actual energy product is the numerical grade minus one in units of MGOe, i.e. a SmCo26 magnet has an energy product of 25MGOe at 20°C.
The grades assumed by FEMM are listed below in Tables 1 and 2.
| Grade | \(BH_{max}\), MGOe | \(B_r\), T | \(B_r\), kG | \(H_{cB}\), kA/m | \(H_{cB}\), kOe | \(\sigma\), MS/m |
| SmCo18 | 17 | 0.837 | 8.37 | 647 | 8.13 | 20 |
| SmCo20 | 19 | 0.885 | 8.85 | 684 | 8.59 | 20 |
| SmCo22 | 21 | 0.930 | 9.30 | 719 | 9.03 | 20 |
| SmCo24 | 23 | 0.973 | 9.73 | 752 | 9.45 | 20 |
Table 1: Typical SmCo1:5 Properties
| Grade | \(BH_{max}\), MGOe | \(B_r\), T | \(B_r\), kG | \(H_{cB}\), kA/m | \(H_{cB}\), kOe | \(\sigma\), MS/m |
| SmCo24 | 23 | 1.006 | 10.06 | 728 | 9.15 | 1.16 |
| SmCo26 | 25 | 1.049 | 10.49 | 759 | 9.53 | 1.16 |
| SmCo28 | 27 | 1.090 | 10.90 | 789 | 9.91 | 1.16 |
| SmCo30 | 29 | 1.130 | 11.30 | 817 | 10.27 | 1.16 |
| SmCo32 | 31 | 1.1679 | 11.68 | 845 | 10.62 | 1.16 |
Table 2: Typical SmCo2:17 Properties