Combined effects of transition metal (Ni and Rh) substitution and annealing/quenching on physical properties of CaFe${}_2$As${}_2$

Abstract

We performed systematic studies of the combined effects of annealing/quenching temperature ({\itshape T}${}_{A/Q}$) and T = Ni, Rh substitution ({\itshape x}) on the physical properties of Ca(Fe${}_{1-x}$T${}_x$)${}_2$As${}_2$. We constructed two-dimensional, {\itshape T}${}_{A/Q}$-{\itshape x} phase diagrams for the low-temperature states for both substitutions to map out the relations between ground states and compared them with that of Co-substitution. Ni-substitution, which brings one more extra electron per substituted atom and suppresses the {\itshape c}-lattice parameter at roughly the same rate as Co-substitution, leads to a similar parameter range of antiferromagnetic/orthorhombic in the {\itshape T}${}_{A/Q}$-{\itshape x} space as that found for Co-substitution, but has the parameter range for superconductivity shrunk (roughly by a factor of two). This result is similar to what is found when Co- and Ni-substituted BaFe${}_2$As${}_2$ are compared. On the other hand, Rh-substitution, which brings the same amount of extra electrons as does Co-substitution, but suppresses the {\itshape c}-lattice parameter more rapidly, has a different phase diagram. The collapsed tetragonal phase exists much more pervasively, to the exclusion of the normal, paramagnetic, tetragonal phase. The range of antiferromagnetic/orthorhombic phase space is noticeably reduced, and the superconducting region is substantially suppressed, essentially truncated by the collapsed tetragonal phase. In addition, we found that whereas for Co-substitution there was no difference between phase diagrams for samples annealed for one or seven days, for Ni- and Rh- substitutions a second, reversible, effect of annealing was revealed by seven-day anneals.

References in corpus (12)

• Superconductivity at 22 K in Co-doped BaFe2As2 Crystals
• Pressure induced superconductivity in CaFe${}_2$As${}_2$
• Effects of Co substitution on thermodynamic and transport properties and anisotropic $H_{c2}$ in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ single crystals
• Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
• Lattice and magnetic instabilities in CaFe2As2: A single crystal neutron diffraction study
• First order structural phase transition in CaFe${}_2$As${}_2$
• The Unprecedented Giant Coupling of Fe-spin State and the As-As Hybridization in Iron-Pnictide
• The Absence of Superconductivity in Single Phase CaFe2As2 under Hydrostatic Pressure
• Lattice collapse and quenching of magnetism in CaFe2As2 under pressure: A single crystal neutron and x-ray diffraction investigation
• Pressure-induced superconductivity in single crystal CaFe2As2
• Presure-Induced Superconducting State of Antiferromagnetic CaFe${}_2$As${}_2$
• Suppression of antiferromagnetic spin fluctuations in the collapsed tetragonal phase of CaFe2As2

Cited by in corpus (4)

• Crystal growth and the electronic phase diagram of the 4$d$ doped Na${}_{1-\delta }$Fe${}_{1-x}$Rh${}_x$As in comparison with 3$d$ doped Na${}_{1-\delta }$Fe${}_{1-x}$Co${}_x$As
• Wavefunctions, electronic localization and bonding properties for correlated materials beyond the Kohn-Sham formalism
• Suppression of magnetic order in CaCo${}_{1.86}$As${}_2$ with Fe substitution: Magnetization, neutron diffraction, and x-ray diffraction studies of Ca(Co${}_{1-x}$Fe${}_x$)${}_y$As${}_2$
• Signature of Unconventional Superconductivity in the High Temperature Normal State Resistivity