We report how the thermopower of complex transition-metal oxides is susceptible to small changes in material parameters. In the A-site ordered perovskite oxide R(2/3)Cu(3)Ti(3.6)Ru(0.4)O(12), the thermopower changes from 15 to -100 microV K(-1) at 300 K in going from R = La to Er. We associate this with the hybridization between Cu 3d and Ru 4d electrons, which depends on R. For stronger hybridization, the Cu 3d electrons become more itinerant leading to positive thermopower. In the A-site ordered perovskite cobalt oxide Sr(3)YCo(4)O(10.5), the spin state of the Co(3+) ions determines the magnitude of the thermopower, where partial isovalent substitution (Ca for Sr and Rh for Co) enhances the thermopower whilst keeping the resistivity intact. These substitutions stabilize the low spin state of the Co(3+) ions, which affects the thermopower through the entropy of the background for the carriers. We propose that the control of the magnetism plays a pivotal role in determining the thermopower in a certain class of complex oxides.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/b914661j | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Deletion of metal transporter Zip14 reduces major histocompatibility complex II expression in murine small intestinal epithelial cells.
Proc Natl Acad Sci U S A
January 2025
Center for Nutritional Sciences, Food Science and Human Nutrition Department, College of Agricultural and Life Sciences, University of Florida, Gainesville, FL 32611.
Documented worldwide, impaired immunity is a cardinal signature resulting from loss of dietary zinc, an essential micronutrient. A steady supply of zinc to meet cellular requirements is regulated by an array of zinc transporters. Deletion of the transporter Zip14 (Slc39a14) in mice produced intestinal inflammation.
View Article and Find Full Text PDFThe Carbene Chemistry of -Sulfonyl Hydrazones: The Past, Present, and Future.
Chem Rev
January 2025
Department of Chemistry, Northeast Normal University, Changchun 130024, China.
-Sulfonyl hydrazones have been extensively used as operationally safe carbene precursors in modern organic synthesis due to their ready availability, facile functionalization, and environmental benignity. Over the past two decades, there has been tremendous progress in the carbene chemistry of -sulfonyl hydrazones in the presence of transition metal catalysts, under metal-free conditions, or using photocatalysts under photoirradiation conditions. Many carbene transfer reactions of -sulfonyl hydrazones are unique and cannot be achieved by any alternative methods.
View Article and Find Full Text PDFFerroelectric/Electric-Double-Layer-Modulated Synaptic Thin Film Transistors toward an Artificial Tactile Perception System.
ACS Appl Mater Interfaces
January 2025
Department of Materials Science, National Engineering Lab for TFT-LCD Materials and Technologies, Fudan University, Shanghai 200433, China.
Tactile sensation and recognition in the human brain are indispensable for interaction between the human body and the surrounding environment. It is quite significant for intelligent robots to simulate human perception and decision-making functions in a more human-like way to perform complex tasks. A combination of tactile piezoelectric sensors with neuromorphic transistors provides an alternative way to achieve perception and cognition functions for intelligent robots in human-machine interaction scenarios.
View Article and Find Full Text PDFRational Synthesis of Highly Fluorescent N, S Co-Doped Carbon Dots Using Biogenic Creatinine for Cu Analysis in Drinking Water.
Luminescence
January 2025
Analytical Chemistry Department, Faculty of Pharmacy, Helwan University, Cairo, Egypt.
Herein, highly fluorescent sulfur and nitrogen co-doped carbon dots (N, S-CDs) had been employed as a fluorescent probe to analyze Cu in drinking water. The biogenic creatinine is known to form a stable complex with Cu; hence, it was rationally selected as a bioinspired nitrogen substrate for the first time to enhance N, S-CDs selectivity towards Cu. Moreover, the literature was surveyed to guide the selection of sulfur and carbon sources to optimize N, S-CDs quantum yield (QY), so thiourea and disodium edetate are co-carbonized with biogenic creatinine at 270°C for 40 min and characterized using different techniques.
View Article and Find Full Text PDFActive site-inspired multicopper laccase-like nanozymes for detection of phenolic and catecholamine compounds.
Anal Chim Acta
January 2025
School of Medical Devices, Shenyang Pharmaceutical University, No. 103, Wenhua Road, Shenyang, 110016, PR China. Electronic address:
Phenolic compounds are typical organic pollutants which cause severe human health problems due to their teratogenesis, carcinogenesis, neurotoxicity, immunotoxicity and endocrine disruption. Natural laccase is a multicopper oxidase existing in bacteria, plants, and insects, which can accelerate the transformation of phenolic compounds to their less hazardous oxidized products under mild conditions without harmful byproducts. Despite eco-environmentally friendly property of laccase, it still faces constraints of widespread application attribute to its high cost, complex preparation, and vulnerability.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!