Kuhns P L, Hoch M J R, Moulton W G, Reyes A P, Wu J, Leighton C
National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.
Phys Rev Lett. 2003 Sep 19;91(12):127202. doi: 10.1103/PhysRevLett.91.127202. Epub 2003 Sep 16.
59Co NMR measurements on La1-xSrxCoO3 reported here establish unequivocally, for the first time, the coexistence of ferromagnetic regions, spin-glass regions, and hole-poor low spin regions at all x values from 0.1 to 0.5. A zero external field NMR spectrum, which is assigned to the ferromagnetic regions, has a spectral shape that is nearly x independent at 1.9 K, as are the relaxation times, T1 and T2. The integrated spectral area increases rapidly with x up to x = 0.2 and then decreases slightly for larger x. In a field of 9.97 T, a narrow NMR line is observed at 102 MHz, identical to that found in x = 0 samples in previous work. The integrated intensity of this spectrum decreases rapidly with increasing x, and is ascribed to hole-poor low spin regions. Beneath this spectrum, a third broad line, with a peak at 100 MHz, is assigned to a spin- or cluster-glass-like phase.
本文报道的对La1-xSrxCoO3进行的59Co核磁共振测量首次明确证实，在x值从0.1到0.5的所有情况下，铁磁区域、自旋玻璃区域和空穴贫乏的低自旋区域共存。一个被归因于铁磁区域的零外场核磁共振谱，其谱形在1.9 K时几乎与x无关，弛豫时间T1和T2也是如此。积分谱面积随x迅速增加，直至x = 0.2，然后对于更大的x略有下降。在9.97 T的磁场中，在102 MHz处观察到一条窄的核磁共振线，与之前工作中在x = 0样品中发现的相同。该谱的积分强度随x增加而迅速下降，归因于空穴贫乏的低自旋区域。在该谱之下，一条在100 MHz处有峰值的第三条宽线被归因于类似自旋或团簇玻璃的相。
