Double perovskite Y2NiIrO6 is a ferrimagnetic material with Curie temperature of 192 K. It has drawn wide attention owing to its remarkable exchange-bias effect. Here, we studied the low-temperature crystal structure, electron transport properties and magnetoresistance of Y2NiIrO6. The crystal structure under 130 K is almost identical with that of room-temperature. The material shows semiconducting behavior in the temperature range of 130 to 300 K. Above Curie temperature it can be well describe as Efros-Shklovskii variable-range hopping model. Below Curie temperature, a departure occurs due to the forming of long-range ferrimagnetic ordering. It is interesting to find that the magnetic ordering results into negative magneto-resistance. Moreover, giant magnetoresistance up to –10% is induced by cooling field of 7.0 T. This mechanism of this remarkable effect provides a new boulevard to discover new type of giant magneto-resistance materials.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |