Lejda Katarzyna, Drygaś Mariusz, Janik Jerzy F, Szczytko Jacek, Twardowski Andrzej, Olejniczak Zbigniew
Faculty of Energy and Fuels, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow, Poland.
Faculty of Physics, Institute of Experimental Physics, University of Warsaw, Pasteura 2, 02-093 Warszawa, Poland.
Materials (Basel). 2020 Aug 7;13(16):3487. doi: 10.3390/ma13163487.
High energy ball milling is used to make first the quaternary sulfide CuZnSnS raw nanopowders from two different precursor systems. The mechanochemical reactions in this step afford cubic pre-kesterite with defunct semiconducting properties and showing no solid-state Cu and Sn MAS NMR spectra. In the second step, each of the milled raw materials is annealed at 500 and 550 °C under argon to result in tetragonal kesterite nanopowders with the anticipated UV-Vis-determined energy band gap and qualitatively correct NMR characteristics. The magnetic properties of all materials are measured with SQUID magnetometer and confirm the pre-kesterite samples to show typical paramagnetism with a weak ferromagnetic component whereas all the kesterite samples to exhibit only paramagnetism of relatively decreased magnitude. Upon conditioning in ambient air for 3 months, a pronounced increase of paramagnetism is observed in all materials. Correlations between the magnetic and spectroscopic properties of the nanopowders including impact of oxidation are discussed. The magnetic measurements coupled with NMR spectroscopy appear to be indispensable for comprehensive kesterite evaluation.
高能球磨首先用于从两种不同的前驱体体系制备四元硫化物CuZnSnS原始纳米粉末。此步骤中的机械化学反应生成具有失效半导体性能且无固态铜和锡的MAS NMR谱的立方前硫锡铜矿。在第二步中，将每种研磨后的原料在氩气气氛下于500和550℃退火，得到具有预期的紫外可见光谱测定的能带隙和定性正确的NMR特性的四方硫锡铜矿纳米粉末。使用超导量子干涉仪磁力计测量所有材料的磁性，证实前硫锡铜矿样品表现出具有弱铁磁成分的典型顺磁性，而所有硫锡铜矿样品仅表现出相对降低幅度的顺磁性。在环境空气中放置3个月后，观察到所有材料的顺磁性都有明显增加。讨论了纳米粉末的磁性和光谱性质之间的相关性，包括氧化的影响。磁性测量与NMR光谱相结合对于全面评估硫锡铜矿似乎是必不可少的。
