The Crystallographic and Magnetoresistance of CaF2 Doped Nd0.67Sr0.33MnO3 Compounds

✍ Scribed by Yongquan Guo; Yaocheng Liu; Kun Tao; Heping Zhou; Roger Wäplling

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 140 KB
• Volume: 148
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8442

✦ Synopsis

We have studied crystal structures and the giant magnetoresistance of 6uoride Nd 0.67 Sr 0.33 MnO 3 compounds. The experimental results show that the CaF 2 dopant can stabilize the original crystal structure of Nd 0.67 Sr 0.33 MnO 3 compounds. The lattice spacings and unit cell volumes of these 6uoride compounds decrease with CaF 2 doping. The Rietveld pro5le 5tting technique has been used to re5ne the crystal structures of these compounds. The space group of those compounds is Pbnm, Z‫.4؍‬ The F anion prefers to occupy the 8d crystal position. All of these 6uoride compounds are ferromagnetic; their Curie temperatures decrease with CaF 2 doping. However, the giant magnetoresistance ratio of these 6uoride compounds increases. A magnetoresistance ratio as high as 99.2% is obtained at an applied 5eld of 5 T.