Predicted lithium–iron compounds under high pressure

RSC Advances ◽  
2016 ◽  
Vol 6 (71) ◽  
pp. 66721-66728 ◽  
Author(s):  
Yuanyuan Zhou ◽  
Qiang Xu ◽  
Chunye Zhu ◽  
Qian Li ◽  
Hanyu Liu ◽  
...  

Li–Fe intermetallics under pressure adopt host–guest-like structures similar to the self-clathrate incommensurate phases of group I and II elements.

2021 ◽  
Vol 86 ◽  
pp. 103738
Author(s):  
Xi-Yue Li ◽  
Dong-Liang Zhong ◽  
Peter Englezos ◽  
Yi-Yu Lu ◽  
Jin Yan ◽  
...  

2014 ◽  
Vol 9 (1) ◽  
pp. 209-228
Author(s):  
Anita Kasabova

Abstract How the self perceives reality is a traditional topic of research across several disciplines. I examine the perceived self on Facebook, as a case-study of self-knowledge on „classical” social media. Following Blascovich & Bailenson (2011), I consider the distinction between the real and the virtual as relative. Perceptual self-knowledge, filtered through social media, requires rethinking the perceived self in terms of social reality (Neisser, 1993). This claim dovetails Jenkins’s (2013) notion of the self as an active participant in consumption. I argue that the perceived self in social media could be conceived in terms of how it would like to be perceived and appraised by its virtual audience. Using Neisser’s (1993) typology of self-knowledge and Castañeda’s (1983) theory of I-guises, I analyse seven samples from Anglo-American and Bulgarian Facebook sites and show that the perceived self produces itself online as a captivating presence with a credible story. My samples are taken from FB community pages with negligible cultural differences across an online teenage/twens (twixter) age group. I then discuss some problematic aspects of the perceived self online, as well as recent critiques of technoconsumerism.


Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 145 ◽  
Author(s):  
Julia-Maria Hübner ◽  
Lev Akselrud ◽  
Walter Schnelle ◽  
Ulrich Burkhardt ◽  
Matej Bobnar ◽  
...  

BaSi3 is obtained at pressures between 12(2) and 15(2) GPa and temperatures from 800(80) and 1050(105) K applied for one to five hours before quenching. The new trisilicide crystallizes in the space group I 4 ¯ 2m (no. 121) and adopts a unique atomic arrangement which is a distorted variant of the CaGe3 type. At ambient pressure and 570(5) K, the compound decomposes in an exothermal reaction into (hP3)BaSi2 and two amorphous silicon-rich phases. Chemical bonding analysis reveals covalent bonding in the silicon partial structure and polar multicenter interactions between the silicon layers and the barium atoms. The temperature dependence of electrical resistivity and magnetic susceptibility measurements indicate metallic behavior.


1998 ◽  
Author(s):  
Gennady A. Baranov ◽  
V. P. Tomashevich ◽  
P. V. Tomashevich

2011 ◽  
Vol 194-196 ◽  
pp. 818-824
Author(s):  
Ye Song ◽  
Qiu Mei Ye ◽  
Peng Liu ◽  
Jun Jun Hu ◽  
Xin Hua Zhu

The formation process of a petal-like morphology on the surface of porous anodic alumina (PAA) is discussed in detail. During the anodizing process, the electronic current is produced within the growing oxide, which results in the oxygen evolution at the pore bottom. The pressure of the oxygen bubbles increases along with the anodizing process, and their high pressure acts as a driving-force of the micro-gas-flow, resulting in the micro-liquid-flow in the pores of PAA. The micro-liquid-flow can flow into each other between a center pore and the nearest neighboring pores. The nanogroove between two pores can be formed due to the dissolving effect during the process of micro-liquid-flow between the two pores. This leads to the formation of the petal-like morphology on the PAA surface. As the micro-liquid-flow leaves off the pore bottom, there a local vacuum is formed. This local vacuum behaves as a driving-force of the micro-liquid-flow, making the electrolyte renovated in the nanopores. The renovated electrolyte can provide enough anions or impurity centers, which are the cause of the generation of the electronic current. The self-organizing for the petal-like morphology on PAA surface is mainly dependent upon the high pressure of the oxygen bubbles and the local vacuum produced at the pore bottom. The present results may help us to understand the nature of the self-organization in the porous anodic oxides.


2020 ◽  
Author(s):  
Xiaoli Wang ◽  
Xiaolei Feng ◽  
Jianfu Li ◽  
Dalar Khodagholian ◽  
Jiani Lin ◽  
...  

Abstract We demonstrate a remarkable change of chemical trend of iron under high pressure that is of great importance for understanding the distribution of elements in the Earth’s mantle and core. Using a massive-scale first principles study, we show that while reacting with p-block elements under increasing pressure from ambient to that of Erath’s core, iron tends to reverse its chemical nature, changing from an electron donor (reductant) to an electron acceptor, and oxidizes p-block elements. Such reverse chemistry significantly impacts the stoichiometries, bond types and strengths, structures and properties of iron compounds under deep planetary conditions, making many p-block elements that are conventionally labeled lithophile or chalcophile to highly siderophile. The chemical binding strengths with iron show an inverse correlation with the depletion of p-block elements in silicate Earth. Furthermore, silicon shows a distinct anomaly in its bonding to iron, which suggests silicon may readily be incorporated into Earth’s core.


2019 ◽  
Vol 23 (3) ◽  
pp. 191-198
Author(s):  
Penghui Luo ◽  
Shitao Zhang ◽  
Yimin Tian ◽  
Fei Ding ◽  
Zongming Xu

The column height of earth forest is generally 8~30m in yuanmou county of yunnan province, which is far higher than the self-supporting height of general soil column. Ferruginous cement is an important reason for formation of the tall and erect columnar soil. Macroscopic physical and mechanical tests confirmed that the strength of the stratum containing ferruginous cement was much higher than that of the formation without ferruginous cement. The microstructure and morphology of ferruginous cement were analyzed by SEM and EDS. It is found that ferruginous cement is mainly composed of iron compounds and clay minerals, which only exists in certain stratum. In the process of growth, Iron compounds chemically bond with clay minerals during growth to form ferruginous cements, which first form unique sphere on the surface of particles or clay minerals. It then clumps together and fills the spaces between the particles. Finally, the dispersed particles are connected together to form a stable lamellar spatial structure, which greatly improves the strength of the soil. Through the study of ferruginous cement, the mechanism of this natural curing agent is understood, which enriches the research content in this field.


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