An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The diluted magnetic semiconductor Zn1-xMnxO crystals were synthesized at 430 ℃ for 24 h by hydrothermal method. The mineralizer is 3 mol·L-1 KOH, and fill factor is 35%. The Mn concentration in crystal was determined by electron probe. The atomic percentage of Mn in crystal increases as the concentration of MnCl2·6H2O in precursor increases. The maximum of the Mn concentration in crystal is above 8%. The morphology of the crystal varies with the concentration of MnCl2·6H2O in precursor increases. And they all show the hexagonal feature of ZnO wurtzite. The measurement of magnetism was carried out by using a superconducting quantum interference device (SQUID). The crystals show low-temperature ferromagnetism with Curie temperature of 50 K.
In this paper, the fatigue cracking possibility in different kinds of copper bicrystals with large‐angle grain boundaries (GBs) and copper multicrystals containing some low‐angle GBs are compared. The results showed that the fatigue cracks, in the copper bicrystals, always nucleated firstly along GBs no matter whether the GBs are perpendicular or parallel to the stress axis. Whereas, for the copper multicrystals containing low‐angle GBs, the persistent slip bands (PSBs) are always the preferential sites to initiate fatigue cracks no matter whether low‐angle GBs are perpendicular or parallel to the stress axis. Additionally, the fatigue lives of the GBs, and the [1¯23] and [3¯35] grains in the [1¯23] ⊥ [3¯35] and [5¯913] ⊥ [5¯79] bicrystals were measured at different cyclic stresses and strain amplitudes. The results show that intergranular fracture always occurred prior to transgranular fracture in those bicrystals. The fatigue lives increased in the order of the GB, the [1¯23] and the [3¯35] grains in the [1¯23] ⊥ [3¯35] bicrystal under cyclic tension–tension loading. On the other hand, the fatigue life of the GB in the [5¯913] ⊥ [5¯79] bicrystal is about two to three times higher than that in the [1¯23] ⊥ [3¯35] bicrystal. Based on these experimental results from the copper bicrystals and multicrystals, it is indicated that the possibility of fatigue cracking increased in the order of low‐angle GBs, PSBs and large‐angle GBs. It is suggested that both the PSB–GB mechanism and the step mechanism required for GB fatigue cracking were questionable, and the interaction modes of PSBs with GBs may be more important for intergranular fatigue cracking.