Thermomagnetic generator
AssigneeBASF SE
InventorsGeorg Degen, Bennie Reesink, Ekkehard Brueck
Life of this patent
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Abstract
A thermomagnetic generator which converts thermal energy to electrical energy without intermediate conversion to mechanical work and which works at temperatures in the range from −20° C. to 200° C. comprises a thermomagnetic material selected from, for example, (1) compounds of the general formula (I) (AyBy−1)2+δCwDxEz (I) where A is Mn or Co, B is Fe, Cr or Ni, C, D and E at least two of C, D and E are different, have a non-vanishing concentration and are selected from P, B, Se, Ge, Ga, Si, Sn, N, As and Sb, where at least one of C, D and E is Ge or Si, δ is a number in the range from −0.1 to 0.1, w, x, y, z are numbers in the range from 0 to 1, where w+x+z=1.
Claims9
A thermomagnetic generator,
- which comprises a series of at least three different metal-comprising thermomagnetic materials whose magnetocaloric effect occurs at different temperatures, such that conversion of thermal energy to electrical energy can exploit an enlarged temperature range,
- wherein the at least three materials are selected from the group consisting of
- (1) a compound of formula (I)
- (AyB11−y)2+δCwDxEz (I),
- wherein
- A is Mn or Co,
- B is Fe, Cr or Ni,
- C, D, and E have a non-vanishing concentration and are selected from the group consisting of P, B, Se, Ge, Ga, Si, Sn, N, As, and Sb, whereby at least two of C, D, and E are different, and at least one of C, D, and E is Ge or Si,
- δ is a number in a range from −0.1 to 0.1, and
- w, x, y, z are numbers in a range from 0 to 1, where w+x+z=1;
- (2a) an La- and Fe-comprising compound of formula (II)
- La(FexAl1−x)13Hy or La(FexSi1−x)13Hy (II),
- wherein
- x is a number from 0.7 to 0.95, and
- y is a number from 0 to 3;
- (2b) an La- and Fe-comprising compound of formula (III)
- La(FexAlyCoz)13 or La(FexSiyCoz)13 (III),
- wherein
- x is a number from 0.7 to 0.95,
- Y is a number from 0.05 to 1−x, and
- z is a number from 0.005 to 0.5;
- (2c) an La- and Fe-comprising compound of formula (IV)
- LaMnx Fe2−xGe (IV),
- wherein
- x is a number from 1.7 to 1.95;
- (3) a Heusler alloy of MnTP composition where T is a transition metal and P is a p-doping metal having an electron count per atom e/a in a range from 7 to 8.5;
- (4) a Gd- and Si-comprising compound of formula (V)
- Gd5(SixGe1−x )4 (V),
- wherein x is a number from 0.2 to 1;
- (5) an Fe2P-comprising compound;
- (6) a perovskite manganite;
- (7a) a compound comprising at least one rare earth element and having formula (VI)
- Tb5(Si4−xGex) (VI),
- wherein x=0, 1, 2, 3, or 4,
- (7b) a compound comprising at least one rare earth element and having formula (VII)
- XTiGe (VII),
- wherein X=Dy, Ho, and/or Tm;
- (8a) an Mn- and Sb- or As-comprising compound of formula (VIII)
- Mn2−xZxSb (VIII),
- wherein
- Z is Cr, Cu, Zn, Co, V, As, or Ge,
- x is from 0.01 to 0.5, and
- wherein Sb may be replaced by As when Z is not As;
- and
- (8b) an Ma- and Sb- or As-comprising compound of formula (IX)
- Mn2ZxSb1−x (IX),
- wherein
- Z is Cr, Cu, Zn, Co, V, As, or Ge,
- x is from 0.01 to 0.5, and
- wherein Sb may be replaced by As when Z is not As.
Dependencies are inferred from the claim text.