English
Related papers

Related papers: Dramatic Changes in the Electronic Structure Upon …

200 papers

Single crystal neutron and high-energy x-ray diffraction have identified the phase lines corresponding to transitions between the ambient-pressure tetragonal (T), the antiferromagnetic orthorhombic (O) and the non-magnetic collapsed…

We use angle resolved photoemission spectroscopy (ARPES) to study the band structure of BaFe2As2 and CaFe2As2, two of the parent compounds of the iron arsenic high temperature superconductors. We find clear evidence for band back folding…

First principles FLAPW-GGA method was used for the comparative study of the structural and electronic properties of three related tetragonal ThCr2Si2-type phases KFe2Ch2, where Ch are S, Se, and Te. The main trends in electronic bands,…

Superconductivity · Physics 2011-02-23 I. R. Shein , A. L. Ivanovskii

At ambient pressure CaFe2As2 has been found to undergo a first order phase transition from a high temperature, tetragonal phase to a low temperature orthorhombic / antiferromagnetic phase upon cooling through T ~ 170 K. With the application…

We investigate the electronic structure of CaFe$_2$As$_2$ using high resolution photoemission spectroscopy. Experimental results exhibit three energy bands crossing the Fermi level making hole pockets around the $\Gamma$-point. Temperature…

Superconductivity · Physics 2014-04-03 G. Adhikary , D. Biswas , N. Sahadev , R. Bindu , N. Kumar , S. K. Dhar , A. Thamizhavel , K. Maiti

Temperature dependent measurements of 57Fe Mossbauer spectra on CaFe2As2 single crystals in the tetragonal and collapsed tetragonal phases are reported. Clear features in the temperature dependencies of the isomer shift, relative spectra…

Materials Science · Physics 2016-01-27 Sergey L. Bud'ko , Xiaoming Ma , Milan Tomic , Sheng Ran , Roser Valenti , Paul C. Canfield

In a joint experimental and theoretical study, we investigate the isostructural collapse from the ambient pressure tetragonal phase to a collapsed tetragonal phase for non-superconducting metallic SrFe2As2 and SrFe_1.8Ru_0.2As_2. The…

We present a comprehensive study of the low-energy band structure and Fermi surface (FS) topology of $A$Co$_2$As$_2$ ($A=$ Ca, Sr, Ba, Eu) using high-resolution angle-resolved photoemission spectroscopy. The experimental FS topology and…

Superconductivity · Physics 2021-07-13 R. S. Dhaka , Y. Lee , V. K. Anand , Abhishek Pandey , D. C. Johnston , B. N. Harmon , Adam Kaminski

We use angle-resolved photoemission spectroscopy (ARPES) to study the electronic properties of CaFe2As2 - parent compound of a pnictide superconductor. We find that the structural and magnetic transition is accompanied by a three- to…

We performed an angle-resolved photoemission spectroscopy (ARPES) study of the electronic structure of the CaFe$_2$As$_2$ 122-iron pnictide, a parent compound, and two iron-based superconductors CaFe$_{2-x}$Co$_x$As$_2$ ($x = 0.07$ and…

Superconductivity · Physics 2025-03-05 Marcin Rosmus , Natalia Olszowska , Rafal Kurleto , Zbigniew Bukowski , Pawel Starowicz

Recent investigations of the superconducting iron-arsenide families have highlighted the role of pressure, be it chemical or mechanical, in fostering superconductivity. Here we report that CaFe2As2 undergoes a pressure-induced transition to…

We revisit the electronic structure of BaFe$_2$As$_2$, the archetypal parent compound of the Fe-based superconductors, using angle-resolved photoemission spectroscopy (ARPES). Our high-resolution measurements of samples detwinned by the…

Iron-based compounds (IBS) display a surprising variety of superconducting properties that seems to arise from the strong sensitivity of these systems to tiny details of the lattice structure. In this respect, systems that become…

Inelastic neutron scattering measurements of CaFe2As2 under applied hydrostatic pressure show that the antiferromagnetic spin fluctuations observed in the ambient pressure, paramagnetic, tetragonal (T) phase are strongly suppressed, if not…

We perform first principles calculations on CaFe2As2 under hydrostatic pressure. Our total energy calculations show that though the striped antiferromagnetic (AFM) orthorhombic (OR) phase is favored at P=0, a non-magnetic collapsed…

Strongly Correlated Electrons · Physics 2015-06-05 Michael Widom , Khandker Quader

We use high resolution angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) to investigate the electronic structure of trigonal phase ${\rm PtBi_2}$ (t-${\rm PtBi_2}$), a proposed Weyl semimetal that is…

Mesoscale and Nanoscale Physics · Physics 2025-03-13 Evan O'Leary , Zhuoqi Li , Lin-Lin Wang , Benjamin Schrunk , Andrew Eaton , Paul C. Canfield , Adam Kaminski

The iron-based pnictide LaFe2As2 is not superconducting as-synthesized, but it becomes such below Tc around 12 K upon annealing, as a consequence of a structural transition from a phase with collapsed tetragonal crystal structure to an…

Electronic structure of newly synthesized single crystals of calcium iron arsenide doped with sodium with Tc ranging from 33 to 14 K has been determined by angle-resolved photoemission spectroscopy (ARPES). The measured band dispersion is…

With the proposed Hund's rule correlation picture, i.e. the fluctuating Fe local moments with the As-bridged antiferromagnetic superexchange interactions, the exceptional collapsed tetragonal phase and related phase transitions observed in…

Materials Science · Physics 2011-04-28 Wei Ji , Xun-Wang Yan , Zhong-Yi Lu

The electronic structure of the reentrant superconductor Eu(Fe$_{0.86}$Ir$_{0.14}$)$_{2}$As$_{2}$ (T$_c$ = 22 K) with coexisting ferromagnetic order (T$_M$ = 18 K) is investigated using angle-resolved photoemission spectroscopy (ARPES) and…