Magnetic, structural and superconducting properties of MgC(Ni1 - xFe x)3

Abstract

~ 7K. The Fe doping quickly depresses Tc, completely destroying the superconducting state for x 0.04. The establishment of an ordered magnetic state is only observed for Fe concentration (x > or = 0.3) far above the concentration for which the superconducting state has completely disappeared. An expansion of the lattice with the increase of the Fe content was observed.]]>

Compositional disorder and its influence on the structural, electronic, and magnetic properties ofMgC(Ni1−xCox)3Joseph1, Singh2 2005Phys. Rev. B4110View full textAdd to dashboardCite

“…[13][14][15][16][17][18][19][20][21][22] In none of the above cases, a definite magnetic solution was found feasible. For Co substitutions the experimental results are unambiguous over the fact that T C decreases as Co at.…”

Effects of Hole-Doping on Superconducting Properties in MgCNi3 and its Relation to Magnetism

“…A small amount of unreacted graphite was found for the samples MgC(Ni 1jx Fe x ) 3 due to the excess of C utilized for its synthesis [1,4].…”

“…The preparation of the MgC y (Ni 1jx Fe x ) 3 (x = 0.01, 0.02, 0.1 and y = 0.8, 1.0) samples is described elsewhere [1,4]. We used 57 Fe to prepare the samples MgC y (Ni 0.99 Fe 0.01 ) 3 (y = 0.8, 1.0).…”

“…Early band structure calculations suggested the involving of magnetic interaction in the suppression of superconductivity in hole-doped MgCNi 3 [3]. In fact, hole doping quickly destroy the superconductivity in MgCNi 3 [1,4,5]. Some calculations [5][6][7] showed that hole doping of MgCNi 3 is accompanied by a reduction of the density of states at the Fermi level, which seems to be responsible for the reduced superconductivity, but magnetic ground states are only expected for high hole dopants (Fe, Co) [6] or absolute absence of C [8].…”

On the propensity of magnetism in 3d transition-metal-MgCNi3 alloys

“…Based on a rigid-band picture, it is estimated that approximately 0.5 holes would make MgCNi 3 magnetic [4,6]. However, in experiments, where the required hole doping is accomplished via Fe or Co substitution in Ni sub-lattice of MgCNi 3 , the substituted alloy remains non-magnetic [7][8][9][10][11].…”