Nearly zero temperature coefficient of resistivity in antiperovskite compound CuNMn3

Negative thermal expansion materials: technological key for control of thermal expansion

“…The volume change reaches 2%, which is among the largest for magnetic metals, next to 4% volume change in YMn 2 [44]. Manganese antiperovskites exhibit many other advantageous features such as magnetostriction [61][62][63], magnetocaloric effects [64,65], magnetoresistance effects [66,67], and a low temperature coefficient of resistance [68][69][70], and hence attract great attention as a reservoir of functionalities.…”

Magnetovolume Effect and Negative Thermal Expansion in Mn<SUB>3</SUB>(Cu<SUB>1&minus;<I>x</I></SUB>Ge<I><SUB>x</SUB></I>)N

“…We obtained Mn 3 AN by solid state reaction. 14,15,17) Powders of Mn 2 N and pure element A (purity: 99.9% or higher) were mixed in a bag filled with nitrogen gas and then sealed in a quartz tube under vacuum (<10 À1 Pa). The sealed quartz tube was heated at 760 C for 40-70 h. To obtain a solid solution Mn 3 (A 1Àx B x )N, we mixed Mn 3 AN and Mn 3 BN in an appropriate molar ratio, pressed into a pellet, and sealed it in a quartz tube under vacuum.…”

“…It becomes ferromagnetic (FM) with the spin structure different from À 5g at Curie temperature T C ¼ 143 K, accompanied by the transition from cubic to tetragonal T 1 structure. 8,14) At the magnetic transition, Mn 3 CuN does not exhibit a large change in volume. However, we found that MVE is restored, surprisingly, by substituting Cu with a small amount of Ge and NTE is also exhibited by further Ge doping.…”

“…6,7) Antiperovskite manganese nitrides Mn 3 AN (A ¼ Zn, Ga, etc) are well-known for their large MVE. [8][9][10][11][12][13][14][15] For these nitrides the large volume expansion is triggered by the magnetic transition from the high-temperature (high-T) paramagnetic phase to the low-T antiferromagnetic (AF) ordered phase with the triangular À 5g structure. This expansion is isotropic because the crystal structure remains cubic at the transition.…”

The observation of a positive magnetoresistance and close correlation among lattice, spin, and charge around TC in antipervoskite SnCMn3

“…15 SnCMn 3 belongs to the family of Mn-based antiperovskite compounds which have been investigated for several decades. According to the results of neutron diffraction measurement, SnCMn 3 has a noncollinear ferrimagnetic (FIM) ground state, being constituted of an antiferromagnetic (AFM) lattice and a ferromagnetic (FM) one with perpendicular to each other.…”