Permanent magnets based on rare earth alloys
produced by MMT, Ltd.

Rare-earth permanent magnets produced by Research and production Company MMT, Ltd. feature:

• highest magnetic field values among the industrial magnets;
• super-high coercitivity (demagnetization resistance), unmatched by any other type of permanent magnets;
• enhanced mechanical strength;
• exactly measured thermal and temporal stability of magnetic flux;
• thermal stability up to high temperatures.
  

Application of magnetic elements and systems based on such magnets allows to:

• decrease the weight of magnetic systems and elements;
• decrease the dimensions of magnetic elements and systems;
• develop new approaches to design of magnetic systems for various applications;
• realize entirely new magnetic systems with parameters unmatched even by electromagnets and solenoids.
  
  

Properties of Nd-Fe-B magnets produced by our Company, according to the technical specifications ÒÓ 1984-001-18785310-2003 and ÒÓ 3498-002-18785310-2003, are given in Table 1. Magnets of type Sm-Co are produced in accordance with ÃÎÑÒ 21559 (Russian state technical standard).

Table 1. Basic parameters of NdFeB type magnets, produced by R&D Company «MMT» (according to ÒÓ 1984-001-18785310-2003)

Type	Br, kGsOersted		Hcb, kOersted		(BH)max, MGsOersted		Hcj, kOersted	RTCI, %°C-1
	min	max	min	max	min	max
MAEP43ML	13.0	13.4	9.8	-	42.0	44.0	10.0	- 0.12
MAEP34ML	11.6	12.0	11.0	11.6	32.0	32.6	12.0	- 0.12
MAEP40ML	12.6	13.0	12.4	12.8	39.0	42.0	13.0	- 0.12
MAEP36AL	11.8	12.4	11.6	12.2	34.0	38.0	17.0	- 0.12
MAEP32HL	11.2	11.6	11.0	11.4	31.0	33.0	22.0	- 0.12
MAEP30HsL	10.8	11.2	10.6	11.0	29.0	31.0	27.0	- 0.12
MAEP38Als	12.2	12.6	12.0	12.4	37.0	39.0	17.0	- 0.12
MAEP35HLs	11.7	12.1	11.5	11.9	34.0	36.0	22.0	-0.12
MAEP33HsLs	11.4	11.8	11.2	11.6	32.0	24.0	27.0	- 0.12
MAEP30HSs	10.8	11.2	10.6	11.0	29.0	31.0	18.0	-0.06

Type	Br, Tesla		Hcb, kA/m		(BH)max, kJ/m3		Hcj, kA/m	RTCI, %°C-1
	min	max	min	max	min	max
MAEP43ML	1.30	1.34	785	-	335	355	800	- 0.12
MAEP34ML	1.16	1.20	880	930	255	290	960	- 0.12
MAEP40ML	1.26	1.30	990	1020	310	335	1050	- 0.12
MAEP36AL	1.18	1.24	930	980	270	305	1350	- 0.12
MAEP32HL	1.12	1.16	880	910	250	265	1750	- 0.12
MAEP30HsL	1.08	1.12	850	880	230	250	2150	- 0.12
MAEP38Als	1.22	1.26	960	990	295	310	1350	- 0.12
MAEP35HLs	1.17	1.21	920	950	270	290	1750	-0.12
MAEP33HsLs	1.14	1.18	900	930	255	270	2150	- 0.12
MAEP30HSs	1.08	1.12	850	880	230	250	1450	-0.06
Note: Br, kGauss(Tesla) - residual magnetic induction, Hcb, kOersted(kA/m) - induction coercive force, (BH)max, MGaussOersted(kJ/m3) - maximum energy product, Hcj, kOersted(kA/m) - magnetization coercive force, RTCI, %/°Ñ - Reversible temperature coefficient of induction in the temperature range of 20 - 100°Ñ.

More detailed information concerning the magnets of type MAEP and specific measurement techniques is given in the Technical specifications:
ÒÓ 1984-001-18785310-2003 «Hard magnetic materials based on iron alloys containing neodymium and boron».

MMT Ltd. produces a wide range of rare-earth permanent magnet types (size, form, magnetization direction, etc.) This variety of magnet types is described by the technical specifications ÒÓ 3498-002-18785310-2003 «Sintered permanent magnets based on iron alloys containing neodymium and boron». A few examples of magnet types produced by R&D company MMT is given in Section «MMT magnet types».

Hysteresis characteristics of Sm-Co alloys produced by MMT comply with the requirements of Russian state standadrd ÃÎÑÒ 21559-88 «Sintered hard magnetic materials». A more detailed description of rare-earth sintered hard magnetic materials is given in the paper: Lukin A.A., Dormidontov A.G. in the Russian journal "Radiotechnika" (Radio technology), 2001, ¹2, pp. 87-93.

Note that the mentioned variety of magnets is produced both for direct shipment to the customers and for their application in magnetic systems produced by the Second production department of MMT Ltd. This department produces ready magnetic systems with parameters required by the Customer.

Parameters of the basic types of industrial permanent magnets are shown for comparison in Figure 1 (Hysteresis characteristics of the most common types of industrial permanent magnets) and the following Tables:
2. Magnetic parameters of the most common types of rare earth magnets
3. Electric and calorimetric parameters
4. Mechanical parameters

Magnets of Nd-Fe-B type exhibit a unique combination of magnetic hysteresis parameters (B_r, H_cb, H_cj è (BH)_max) unmatched by any other type of permanent magnets.

This allows an essential decrease of size, weight, and, as a rule, cost of magnetic systems (elements) when such magnets are used for upgrade of devices designed for other magnet types.

However, the main advantage of this unique combination of parameters is feasibility of a new fundamental approach to the development of magnetic systems for a wide range of applications. Nd-Fe-B magnets allow to realize entirely new magnetic system designs with parameters unmatched even by electromagnets.