<i>Ab initio</i>investigation of FeAs/GaAs heterostructures for potential spintronic and superconducting applications

Griffin, Sinéad M.; Spaldin, Nicola A.

doi:10.1103/physrevb.85.155126

Cited by 7 publications

(8 citation statements)

References 36 publications

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“…Density functional theory (DFT) has been utilised successfully to address many questions regarding the properties of the iron-pnicitide superconductors and the related Fe-As spintronic compounds [17][18][19][20] . The ground-state structural and magnetic properties have been correctly reproduced with DFT, provided due care is taken with the choice of exchange-correlational functional.…”

Section: Introductionmentioning

confidence: 99%

A density functional theory study of FeAs comparing LDA+U, GGA+U and hybrid functionals

Griffin,

Spaldin

2014

Preprint

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We use density functional theory within the local density approximation (LDA), LDA+U, generalised gradient approximation (GGA), GGA+U, and hybrid-functional methods to calculate the properties of iron monoarsenide. FeAs, which forms in the MnP structure, is of current interest for potential spintronic applications as well as being the parent compound for the newly-identified pnictide superconductors. We compare the calculated structural, magnetic and electronic properties obtained using the different functionals to each other and to experiment, and investigate the origin of a recently-reported magnetic spiral. Our results indicate the appropriateness or otherwise of the various functionals for describing FeAs and the related Fe-pnictide superconductors.

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Section: Introductionmentioning

confidence: 99%

A density functional theory study of FeAs comparing LDA+U, GGA+U and hybrid functionals

Griffin,

Spaldin

2014

Preprint

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“…The potential coexistence of half-metallic ferromagnetism and superconductivity may enhance the existing properties of both phenomena, and result in new states of matter [19]. Such coexistence in (Fe, Ga)As-based materials has been consid- ered in the 'ThCr 2 Si 2 ' structure, where they were found to be mutually exclusive due to the nature of the Fe-As bonds [20,21]. The Fe ions favor a striped antiferromagnetic order in these materials; to achieve HMFM a ferromagnetic ground state is required.…”

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confidence: 99%

Prediction of a new class of half-metallic ferromagnets from first principles

Griffin¹,

Neaton²

2017

Phys. Rev. Materials

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Half-metallic ferromagnetism (HMFM) occurs rarely in materials and yet offers great potential for spintronic devices. Recent experiments suggest a class of compounds with the 'ThCr2Si2' (122) structure -isostructural and containing elements common with Fe pnictide-based superconductors -can exhibit HMFM. Here we use ab initio density-functional theory calculations to understand the onset of half-metallicity in this family of materials and explain the appearance of ferromagnetism at a quantum critical point. We also predict new candidate materials with HMFM and high Curie temperatures through A-site alloying.For the past two decades, the field of spintronics has aimed to augment standard charge-based technologies by harnessing phenomena associated with the spin degree of freedom [1,2]. The most promising and sought-after spintronic property is half-metallic ferromagnetism owing to its strong potential for applications such as spinfilters [3,4]. The promise of materials with HMFM is associated with their unusual electronic structure -they are metallic in one spin channel but insulating in the other -resulting in total spin polarization at the Fermi level.Although HMFM has been proposed in oxides[5], sulfides[6], Heuslers[4] and graphene [7], it is extremely rare. (Ga, Mn)As remains the most-studied system with HMFM, given its potential ease of incorporation into existing semiconductor technologies and the significant capabilities for epitaxy (and therefore tunability) of III-V semiconductors [8,9]. Both spin and charge are introduced into GaAs by substituting trivalent Ga 3+ with divalent magnetic ions, Mn 2+ , providing ferromagneticallycoupled spin carriers. However its use in devices has been hampered by the low solubility of Mn in GaAs, limiting its transport and magnetic properties, and resulting in Curie temperatures below room temperature.Recently, evidence of half-metallic ferromagnetism was found in Ba 0.4 Rb 0.6 Mn 2 As 2 with a Curie temperature, T C , of 103 K[10], Ba 0.6 K 0.4 Mn 2 As 2 with a T C of 100 K[11], and (Ba 1−x K x )(Zn 1−y Mn y ) 2 As 2 with a T C of 180 K [12]. These form in a tetragonal 'ThCr 2 Si 2 ' (122) structure, which is isostructural with the high-temperature phase of the (122) Fe-pnictide-based superconductors [13,14]. Varying the transition-metal ion in these 122 pnictide structures leads to a highly-divergent set of phenomena: high-T C superconductivity in Fe-based materials [15], antiferromagnetic semiconducting behavior in Mn-based compounds [16,17], and non-Fermi-liquid behaviour in YbRh 2 Sr 2 [18]. The potential coexistence of half-metallic ferromagnetism and superconductivity may enhance the existing properties of both phenomena, and result in new states of matter [19]. Such coexistence in (Fe, Ga)As-based materials has been consid- The I4/mmm crystal structure with intralayer AsAs dimer. The calculated spin-polarized density of states for stoichiometric BaMn2As2 with ferromagnetic ordering. The Mn-3d and As-4p orbitals are projected and depicted in purple and green resp...

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“…Density functional theory (DFT) has been utilised successfully [12][13][14][15] to address many questions regarding the properties of the iron-pnicitide superconductors, as well as the related FeAs spintronic compounds that had been widely studied previously [16][17][18][19][20]. The ground-state structural and magnetic properties are correctly reproduced with DFT, provided due care is taken with the choice of exchangecorrelational functional.…”

Section: Introductionmentioning

confidence: 99%

A density functional theory study of the influence of exchange-correlation functionals on the properties of FeAs

Griffin

Spaldin

2017

J. Phys.: Condens. Matter

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We use density functional theory within the local density approximation (LDA), LDA + U, generalised gradient approximation (GGA), GGA + U, and hybrid-functional methods to calculate the properties of iron monoarsenide. FeAs, which forms in the MnP structure, is of current interest for potential spintronic applications as well as being the parent compound for the pnictide superconductors. We compare the calculated structural, magnetic and electronic properties obtained using the different functionals to each other and to experiment, and investigate the origin of a recently reported magnetic spiral. Our results indicate the appropriateness or otherwise of the various functionals for describing FeAs and the related Fe-pnictide superconductors.

show abstract

Ab initioinvestigation of FeAs/GaAs heterostructures for potential spintronic and superconducting applications

Cited by 7 publications

References 36 publications

A density functional theory study of FeAs comparing LDA+U, GGA+U and hybrid functionals

A density functional theory study of FeAs comparing LDA+U, GGA+U and hybrid functionals

Prediction of a new class of half-metallic ferromagnets from first principles

A density functional theory study of the influence of exchange-correlation functionals on the properties of FeAs

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