Evidence of hydrogen content and monovalent Ni oxidation state in non-superconducting bulk anchored infinite-layer nickelates DOI Creative Commons
Javier Gainza, Carlos A. López, Federico Serrano‐Sánchez

и другие.

Cell Reports Physical Science, Год журнала: 2023, Номер 4(12), С. 101724 - 101724

Опубликована: Дек. 1, 2023

Since superconductivity was first reported in nickelate thin films, many studies have been published about this family of materials, and different hypotheses proposed for explaining the mechanisms structural dependence. Here, we report synthesis anchored infinite-layer LaNi0.9Al0.1O2.1 its hole-doped derivatives by topotactic reduction from La1−xSrxNi0.9Al0.1O3 rhombohedral perovskites. LaNiO2 constitute a new high-temperature superconductors, with same structure as high-Tc cuprates but based on nickel, only showing films now. We describe strategy to stabilize bulk: presence Al at octahedral sites helps stabilize/anchor structure. The reasons bulk being non-superconductors are hotly debated literature. An important question is whether there some hydrogen incorporated into during process LaNiO3 LaNiO2, predicted theoretically not experimentally. Our neutron powder diffraction data show that, indeed, occupies centers Ni–O squares, spectroscopic evidence EELS XAS suggests that Ni reduced Ni+ oxidation state, consistent crystallochemical data.

Язык: Английский

Critical role of hydrogen for superconductivity in nickelates DOI
Xiang Ding, Charles C. Tam, Xuelei Sui

и другие.

Nature, Год журнала: 2023, Номер 615(7950), С. 50 - 55

Опубликована: Март 1, 2023

Язык: Английский

Процитировано

85
Superconducting Nd 1− x Eu x NiO 2 thin films using in situ synthesis DOI Creative Commons
W. Wei, Dung Vu, Zhan Zhang

и другие.

Science Advances, Год журнала: 2023, Номер 9(27)

Опубликована: Июль 5, 2023

We report on superconductivity in Nd 1− x Eu NiO 2 using as a 4f dopant of the parent NdNiO infinite-layer compound. use an all–in situ molecular beam epitaxy reduction process to achieve superconducting phase, providing alternate method ex CaH induce nickelates. The samples exhibit step-terrace structure their surfaces, have T c onset 21 K at = 0.25, and large upper critical field that may be related doping.

Язык: Английский

Процитировано

34
Synthesis of thin film infinite-layer nickelates by atomic hydrogen reduction: Clarifying the role of the capping layer DOI Creative Commons
C. T. Parzyck, V. Anil, Yi Wu

и другие.

APL Materials, Год журнала: 2024, Номер 12(3)

Опубликована: Март 1, 2024

We present an integrated procedure for the synthesis of infinite-layer nickelates using molecular-beam epitaxy with gas-phase reduction by atomic hydrogen. first discuss challenges in growth and characterization perovskite NdNiO3/SrTiO3, arising from post crack formation stoichiometric films. then detail a fully reducing NdNiO3 films to phase, NdNiO2, hydrogen; resulting display excellent structural quality, smooth surfaces, lower residual resistivities than reduced other methods. utilize situ nature this technique investigate role that SrTiO3 capping layers play process, illustrating their importance preventing secondary phases at exposed nickelate surface. A comparative bulk- surface-sensitive study indicates polycrystalline crust on film surface serves limit process.

Язык: Английский

Процитировано

12
Synthesis and physical properties of LaNiO2 crystals DOI Creative Commons
Pascal Puphal, Björn Wehinger, Jürgen Nuß

и другие.

Physical Review Materials, Год журнала: 2023, Номер 7(1)

Опубликована: Янв. 30, 2023

Infinite-layer (IL) nickelates are an emerging family of superconductors whose similarities and differences to cuprate under intense debate. To date, the IL phase can only be reached via topotactic oxygen reduction perovskite phase, using H$_2$ gas or reducing agents such as CaH$_2$. While method has been widely employed on thin film polycrystalline powder samples, La$_{1-x}$Ca$_x$NiO$_3$ single-crystals with lateral dimensions up 150 $\mu$m was achieved recently, indirect contact Here we report transformation much larger LaNiO$_3$ crystals more than one millimeter, direct We characterize crystalline, magnetic, electronic properties obtained LaNiO$_{2}$ by single-crystal x-ray diffraction (XRD), magnetometry, electrical transport, photoelectron spectroscopy (XPS) measurements. The amount incorporated hydrogen due process is determined a extraction method. In addition, investigate evolution lattice parameters hydrostatic pressure 12 GPa, high-resolution synchrotron XRD. Furthermore, provide comparison several physical their counterparts.

Язык: Английский

Процитировано

19
ToF-SIMS in material research: A view from nanoscale hydrogen detection DOI
Binod Paudel, Jeffrey A. Dhas, Yadong Zhou

и другие.

Materials Today, Год журнала: 2024, Номер 75, С. 149 - 165

Опубликована: Апрель 27, 2024

Язык: Английский

Процитировано

9
Topotactic hydrogen forms chains in ABO2 nickelate superconductors DOI
Liang Si, Paul Worm, Dachuan Chen

и другие.

Physical review. B./Physical review. B, Год журнала: 2023, Номер 107(16)

Опубликована: Апрель 10, 2023

Despite enormous experimental and theoretical efforts, obtaining generally accepted conclusions regarding the intrinsic magnetic electronic properties of superconducting nickelates remains exceptionally challenging. Experiments show a significant degree uncertainty, indicating hidden factors in synthesized films, which call for further investigations. One those is possibility intercalating hydrogen during chemical reduction process from $\mathrm{Nd}(\mathrm{La}){\mathrm{NiO}}_{3}$ to $\mathrm{Nd}(\mathrm{La}){\mathrm{NiO}}_{2}$ using ${\mathrm{CaH}}_{2}$. While has been detected samples, not much known about its distribution through crystal influence on environment. Here, we tendency toward formation one-dimensional chains infinite-layers ${\mathrm{LaNiO}}_{2}$ superconductors density-functional theory supplemented by dynamical mean-field theory. The such induces coexistence different oxidation states Ni competing phases, possibly explains recently observed charge order nickelate superconductors. Furthermore, it contributes difficulty synthesizing homogeneous determining their ground states. smoking gun detect excess flat phonon modes, are infrared active quite insensitive exact arrangement H atoms.

Язык: Английский

Процитировано

11
Absence of electron-phonon-mediated superconductivity in hydrogen-intercalated nickelates DOI
Simone Di Cataldo, Paul Worm, Liang Si

и другие.

Physical review. B./Physical review. B, Год журнала: 2023, Номер 108(17)

Опубликована: Ноя. 22, 2023

A recent experiment [X. Ding et al., Nature (London) 615, 50 (2023)] indicates that superconductivity in nickelates is restricted to a narrow window of hydrogen concentration, $0.22

Язык: Английский

Процитировано

11
Absence of hydrogen insertion into highly crystalline superconducting infinite layer nickelates DOI

M. Gonzalez,

Anton V. Ievlev, Kyuho Lee

и другие.

Physical Review Materials, Год журнала: 2024, Номер 8(8)

Опубликована: Авг. 12, 2024

The discovery of superconductivity in the infinite layer nickelates introduced a materials system analogous to cuprates for study unconventional superconductivity. synthesis nickelates, (${\mathrm{RNiO}}_{2}$, R = lanthanide) often uses calcium hydride (${\mathrm{CaH}}_{2}$) facilitate deintercalation apical site oxygen atoms from precursor perovskite (${\mathrm{RNiO}}_{3}$) phase via topotactic reduction. However, it remains uncertain whether use ${\mathrm{CaH}}_{2}$ results insertion hydrogen into structure, and if does, what implications are To quantify composition highly crystalline we synthesized ${\mathrm{Nd}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{NiO}}_{2}$ thin films on LSAT substrates conducted time-of-flight secondary ion mass spectroscopy measurements generate depth profiles. We compare density prepared with without ${\mathrm{SrTiO}}_{3}$ capping layer. Additionally, measure content nickelate samples at various doping levels spanning superconducting space, including underdoped, optimally doped, overdoped regime. report no significant increase between phases any measured samples. Furthermore, put an upperbound concentration our ${\mathrm{Nd}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{NiO}}_{2}{\mathrm{H}}_{0.05}$. Our imply that is not responsible emergence nickelates.

Язык: Английский

Процитировано

4
Fingerprints of Topotactic Hydrogen in Nickelate Superconductors DOI Creative Commons
Liang Si, Paul Worm, Karsten Held

и другие.

Crystals, Год журнала: 2022, Номер 12(5), С. 656 - 656

Опубликована: Май 4, 2022

Superconductivity has entered the nickel age marked by enormous experimental and theoretical efforts. Notwithstanding, synthesizing nickelate superconductors remains extremely challenging, not least due to incomplete oxygen reduction topotactic hydrogen. Here, we present density-functional theory calculations, identify a phonon mode as possible indication for hydrogen discuss charge redistribution patterns around impurities.

Язык: Английский

Процитировано

15
Manipulating protons and oxygen vacancies in nickelate oxides via thermochemical dehydration DOI
Haowen Chen, Zihan Xu, Luhan Wei

и другие.

Journal of Materials Chemistry A, Год журнала: 2024, Номер 12(35), С. 23658 - 23669

Опубликована: Янв. 1, 2024

We manipulated the ionic defects (protons and oxygen vacancies) in perovskite nickelates through thermochemical dehydration. quantified correlation between physical properties of vacancy concentration.

Язык: Английский

Процитировано

3