Abstract
Magnetization and specific heat measurements have been carried out on the AB O3 type half-doped (La0.3 Eu0.2) (Ca0.3 Sr0.2) Mn O3 (LE-50) and electron-doped (La0.2 Eu0.25) (Ca0.3 Sr0.25) Mn O3 (LE-55) compounds. These compounds exhibit a metamagnetic transition at low temperatures. In LE-50, the dominant feature of the metamagnetic transition manifests itself at T≲5 K. The transition is sharp and steplike at 2 K with a critical field (HC) of 3.3 kOe and a transition width of 250 Oe becoming broad with a width of ~10 kOe at 3 K. Similarly, in the LE-55 sample, the steplike behavior occurs at T≲3 K with HC =72 kOe, whereas at T>3 K, the transition is much broader. A feature consistent with the metamagnetic transition appears in the specific heat data in these compounds. Such metamagnetic steps have been observed prior to now only in Pr-based manganites. Observation of the same in Eu-based manganites suggests that these steps have no influence of any property intrinsic to Pr ions.
| Original language | English |
|---|---|
| Article number | 10H710 |
| Journal | Journal of Applied Physics |
| Volume | 97 |
| Issue number | 10 |
| DOIs | |
| State | Published - May 15 2005 |
Funding
D.S.R. is thankful to CSIR, India for providing senior research fellowship (SRF). The PSU authors acknowledge the support of NSF Grant No. DMR-0101318. MBS was supported in part by U.S. DOE Contract No. DE-AC05-00OR2272. The authors acknowledge Dr. R. Nirmala and Mr. D. Budhhikot for their help in experiments. FIG. 1. Resistivity vs temperature plots at 0 T , 5 T , and 7 T for the ( La 0.3 Eu 0.2 ) ( Ca 0.3 Sr 0.2 ) Mn O 3 sample. Inset shows the zero-field-cooled (ZFC) and field-cooled magnetization ( M ) in a field of 50 Oe for the same sample. FIG. 2. Magnetization ( M ) vs field ( H ) isotherms at 300 K , 100 K , 75 K , 50 K , 5 K , 3 K , and 2 K for ( La 0.3 Eu 0.2 ) ( Ca 0.3 Sr 0.2 ) Mn O 3 sample. Data near the transition have been acquired at increments of 250 Oe for isotherms at 2 K and 3 K . FIG. 3. Specific heat versus field ( H ) isotherms at 5 K , 3 K , and 2 K for the ( La 0.3 Eu 0.2 ) ( Ca 0.3 Sr 0.2 ) Mn O 3 sample. FIG. 4. (a) Magnetization ( M ) vs field ( H ) isotherms at 3 K , 5 K , and 10 K and (b) specific heat ( C p ) vs field ( H ) isotherms 3 K and 5 K for ( La 0.2 Eu 0.25 ) ( Ca 0.3 Sr 0.25 ) Mn O 3 sample. For M – H curve, data near the transition have been acquired at increments of 500 Oe for isotherms of 2 K and 3 K .