ChemInform Abstract: Coexistence of 3d‐Ferromagnetism and Superconductivity in [(Li_1‐xFe_x)OH](Fe_1‐yLi_y)Se.

Abstract

Coexistence of 3d-Ferromagnetism and Superconductivity in [(Li 1-xFex)OH](Fe1-yLiy)Se. -(Li0.795Fe0.205)OH(Fe0.915Li0.085)Se is hydrothermally prepared from a mixture of iron metal, selenourea, and LiOH in H 2O (autoclave, 150 C, 8 d) and characterized by powder and single crystal XRD, SEM, 57 Fe-Moessbauer spectroscopy, and DFT electronic structure calculations. Electrical resistivity and magnetic susceptibility measurements reveal superconductivity at 43 K, and ferromagnetic ordering near 10 K while superconductivity is retained. The compound crystallizes in the tetragonal space group P4/nmm with Z = 2. The structure contains superconducting (Fe 1-yLiy)Se layers and ferromagnetic (Li1-xFex)OH (x  0.2, y  0.08) layers, which alternate and show anti-PbO type structures. -(PACHMAYR, U.; NITSCHE, F.; LUETKENS, H.; KAMUSELLA, S.; BRUECKNER, F.; SARKAR, R.; KLAUSS, H.-H.; JOHRENDT*, D.; Angew. Chem., Int. Ed. 54 (2015) 1, 293-297, http://dx.

Synthesis and characterization of nanoscale composite particles formed by 2D layers of Cu-Fe sulfide and Mg-based hydroxide

“…The flake-like nanoparticles composed of altering quasi-atomic Cu-Fe-S sulfide and Mg hydroxide sheets are manufactured in the environment-friendly hydrothermal process using common reagents. Such a chalcogenide-hydroxide incommensurate structures looks unusual and complex but there exist a number of natural [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] and synthetic [43][44][45][46][47][48][49][50][51] layered materials, suggesting that those are quite stable and spontaneously assemble via a mechanism that needs to be understood. The composition and then morphology and properties of the materials can be engineered by varying the nature and concentrations of precursors, modifiers, dopants far beyond those used in this case study.…”

“…It is worth recalling, for example, that similar composite of metal (Li and others) hydroxide and iron selenide monolayers are superconductors. [43][44][45][46][47][48][49][50][51] The large surface area, layered structure, and specific surface properties are essential for applications of the nanoscale valleriites as adsorbents, catalysts, sensors, electrode materials, etc. The feasible peptization of the materials paves the way for their utilization as quantum dots and inks or manufacturing thin films on various supports.…”

“…The attempts to synthesize valleriite via thermal sintering or hydrothermal routes have been undertaken [30,[35][36][37]41,42] but mixtures of valleriite with chalcopyrite, magnetite and other byproducts have been obtained. It should be noted that a number of layered composites of lithiumbased and some other hydroxides and iron selenides (Li1-xFex)(OH)FeSe, [43][44][45][46][47] [(Fe,Al)(OH)2][FeSe]1.2, [48] iron sulfides [(Li0.8Fe0.2)OH]Fe(S1-xSex), [49] (NaxFe1-x)(OH)FeS [50] and similar [51] have been prepared and studied with focus on their superconductivity (critical temperature Tc up to 40 K). However, the compounds with alkaline metal hydroxides tend to hydrolysis hindering their exploration and wider exploitation.…”

Coexistence of multiphase superconductivity and ferromagnetism in lithiated iron selenide hydroxide [(Li1−xFexUrban1, Valmianski2, Pachmayr3 et al. 2018Phys. Rev. BSelf Cite4020View full textAdd to dashboardCite

“…Despite the many examples of materials that contain magnetic and SC elements, spatially coexisting SC and FM have been found in only a few systems and at very low temperatures. Significant efforts in the design of new materials by intercalating spacer layers into FeSe crystals lead to the discovery of the FM-SC, lithiated iron selenide hydroxide, [(Li 0.8 Fe 0.2 )OH]FeSe (LISH), with a record for FM-SC systems superconducting transition temperature (T C ) of 43 K. 19 The FM ordering temperature (10 K), is one of the highest and the SC volume fraction is very large, close to 100 % at 2 K, despite the long range magnetic order.…”

“…a for a discussion of length scales see for instance Metallic Superlattices: The Study of Materials at Length Scales Ranging from a Few to Hundreds of Angstroms 13 The physical origin and nature of both transitions and its relation to each other in this class of Febased SC is still under debate. [19][20][21][22][23][24][25][26] LISH is particularly well suited to address the interaction and length scales over which the structure, SC and magnetism interact. In order to study these we have used a combination of conventional structural and magnetic methods, together with magnetic field modulated microwave spectroscopy (MFMMS).…”