来源：ACS PublicationsThe AM2Pn2 (A= Ca, Sr, Ba, Yb, Mg; M = Zn, Cd, Mg; and Pn = N, P, As, Sb, Bi) family of Zintl phases has been known as thermoelectric materials and has recently gained much attention for highly promising materials for solar absorbers in single-junction and tandem solar cells. In this paper, we will, from first principles, explore the entire family of AM2Pn2 compounds in terms of their ground-state structure, thermodynamic stability, and electronic structure. We also perform photoluminescence spectroscopy on bulk powder and thin film samples to verify our results, including t...
Release time:
2025
-
07
-
04
viewed：0
Defects and Defect Association Determine the Actual Entropy of Perovskites Derived from Lanthanum–Calcium Ferrite来源：ACS PublicationsPerovskites La1/2Ca1/2Mn1/3Fe1/3Co1/3O3−δ and iron-rich La3/4Ca1/4Mn1/4Fe1/2Co1/4O3−δ with five cations distributed through the A (La and Ca) and B (Mn, Fe, and Co) positions have been prepared by the combustion method. The corresponding nominal configurational entropies are 1.79R for the former and 1.61R for the latter. The actual configurational entropy may vary from these values due to metal ordering and the presence of oxygen vacancies; this is observed for th...
Release time:
2025
-
07
-
03
viewed：1
来源：ACS PublicationsSolid-state sodium batteries operating at ambient temperatures are promising alternatives to liquid electrolyte batteries, offering improved safety and higher energy density. Among solid-state electrolytes, the ceramic Na-conducting electrolyte Na5YSi4O12 (N5) stands out due to its high Na-ion conductivity, wide electrochemical stability window, and compatibility with high-energy-density cathodes. However, achieving high ionic conductivity at room temperature remains a challenge. In this study, the effect of La doping on the electrochemical properties of an N5 ceramic electr...
Release time:
2025
-
07
-
02
viewed：0
来源：ACS PublicationsThe oxidation state +2 is of interest in rare-earth chemistry since it allows these conventionally redox-inactive metals to be used as reducing agents. However, the divalent oxidation state is difficult to form for most rare-earth elements, and the ensuing compounds are often unstable. Here, we describe an approach to rare-earth reduction chemistry that circumvents the divalent oxidation state by using compounds of trivalent rare earths that store reducing electrons on the dinitrogen ligand [N2]2–, akin to “masked” divalent reactivity. Thus, the dinitrogen complexes [(C...
Release time:
2025
-
07
-
01
viewed：0