1. State Key Laboratory of Solidification ProcessingNorthwestern Polytechnical University Xi'an 710072 P. R. China
2. Key Laboratory of Radiation Detection Materials and DevicesMinistry of Industry and Information Technology Xi'an 710072 P. R. China
3. Materials Science Factory. Instituto de Ciencia de Materiales de Madrid (ICMM‐CSIC) Madrid E‐28049 Spain