Local Chemical Ordering and Negative Thermal Expansion in PtNi Alloy Nanoparticles.

An atomic insight into the local chemical ordering and lattice strain is particular interesting to recent emerging bimetallic nanocatalysts such as PtNi alloys. Here, we reported the atomic distribution, chemical environment, and lattice thermal evolution in full-scale structural description of PtNi alloy nanoparticles (NPs). The different segregation of elements in the well-faceted PtNi nanoparticles is convinced by extended X-ray absorption fine structure (EXAFS).

Zero Thermal Expansion and Semiconducting Properties in PbTiO-Bi(Co, Ti)O Ferroelectric Solid Solutions.

Zero thermal expansion (ZTE) behavior is rare but important for both fundamental studies and practical applications of functional materials. Until now, most available ZTE materials are either electrical insulating oxides or conductive metallic compounds. Very few ZTE materials exhibit the semiconductor feature.

Proton enhanced dynamic battery chemistry for aprotic lithium-oxygen batteries.

Water contamination is generally considered to be detrimental to the performance of aprotic lithium-air batteries, whereas this view is challenged by recent contrasting observations. This has provoked a range of discussions on the role of water and its impact on batteries. In this work, a distinct battery chemistry that prevails in water-contaminated aprotic lithium-oxygen batteries is revealed.

Atomic Linkage Flexibility Tuned Isotropic Negative, Zero, and Positive Thermal Expansion in MZrF (M = Ca, Mn, Fe, Co, Ni, and Zn).

The controllable isotropic thermal expansion with a broad coefficient of thermal expansion (CTE) window is intriguing but remains challenge. Herein we report a cubic MZrF series (M = Ca, Mn, Fe, Co, Ni and Zn), which exhibit controllable thermal expansion over a wide temperature range and with a broader CTE window (-6.69 to +18.

Giant Polarization and High Temperature Monoclinic Phase in a Lead-Free Perovskite of Bi(ZnTi)O-BiFeO.

Lead-free piezoelectrics have attracted increasing attention because of the awareness of lead toxicity to the environment. Here, a new bismuth-based lead-free perovskite, (1 - x)Bi(ZnTi)O-xBiFeO, has been synthesized via a high-pressure and high-temperature method. It exhibits interesting properties of giant polarization, morphotropic phase boundary (MPB), and monoclinic phase.

Large negative thermal expansion in non-perovskite lead-free ferroelectric Sn2P2S6.

Functional materials showing both negative thermal expansion (NTE) and physical performance, such as ferroelectricity and magnetism, have been extensively explored in the past decade. However, among ferroelectrics a remarkable NTE was only found in perovskite-type PbTiO3-based compounds. In this work, a large NTE of -4.

Lattice distortion and orbital hybridization in NdFeO3-PbTiO3 ferroelectric thin films.

Single-phase xNdFeO3-(1 - x)PbTiO3 thin films with different dopant contents were fabricated on the Pt(111)/Ti/SiO2/Si substrate by a sol-gel route. Grain size was influenced by the dopant content effectively. A synchrotron radiation X-ray diffraction study revealed a reduced tetragonality (c/a) of the PbTiO3 lattice in the films.

High-Curie-Temperature Ferromagnetism in (Sc,Fe)F3 Fluorides and its Dependence on Chemical Valence.

A magnetic metal-fluoride system is shown for the first time to have a high Curie temperature (≈545 K). The magnetism correlates intimately with the Fe(2+)/Fe(3+) ratio. As the ratio increases, the weak magnetism displayed by unordered magnetic moments intensifies, and these magnetic moments align in parallel.

Zero thermal expansion and ferromagnetism in cubic Sc(1-x)M(x)F3 (M = Ga, Fe) over a wide temperature range.

The rare physical property of zero thermal expansion (ZTE) is intriguing because neither expansion nor contraction occurs with temperature fluctuations. Most ZTE, however, occurs below room temperature. It is a great challenge to achieve isotropic ZTE at high temperatures.

Ordered structure and thermal expansion in tungsten bronze Pb₂K(0.5)Li(0.5)Nb₅O₁₅.

The crystal structure and thermal expansion behaviors of a new tetragonal tungsten bronze (TTB) ferroelectric, Pb2K(0.5)Li(0.5)Nb5O15, were systematically investigated by selected-area electron diffraction (SAED), neutron powder diffraction, synchrotron X-ray diffraction (XRD), and high-temperature XRD.

Structure and thermal expansion of the tungsten bronze Pb₂KNb₅O₁₅.

The structure and thermal expansion behavior of the tetragonal tungsten bronze oxide Pb2KNb5O15 were investigated by neutron powder diffraction and high-temperature X-ray diffraction. Below the Curie temperature, T(C) (orthorhombic phase, T(C) ≈ 460 °C), the cell parameters a and c increase with temperature, while b decreases. The thermal expansion coefficients are α(a) = 1.

Effects of oxygen vacancy on the electronic structure and multiferroics in sol-gel derived Pb(0.8)Co(0.2)TiO3 thin films.

The single phase Pb(0.8)Co(0.2)TiO3 thin films were synthesized on a Pt/Ti/SiO2/Si substrate by the sol-gel route.

Large remanent polarization and small leakage in sol-gel derived Bi(Zn(1/2)Zr(1/2))O3-PbTiO3 ferroelectric thin films.

The applications of ferroelectric thin films such as the sensitivity of nonvolatile ferroelectric random access memories are closely linked with large remnant polarization. The high-T(C) (1-x)Bi(Zn(1/2)Zr(1/2))O(3)-xPbTiO(3) (x = 0.7-0.