Spin-lattice coupling, Jahn-Teller effect and the influence of the measurement rate in La{sub 0.7}Ca{sub 0.3−x}Sr{sub x}MnO{sub 3} manganites
- Instituto de Ingeniería y Tecnología, Universidad Autónoma de Ciudad Juárez, Av. Del Charro 450 norte, 32310 Ciudad Juárez, Chihuahua, México (Mexico)
- Centro de Investigación en Materiales Avanzados, S. C., Miguel de Cervantes 120, 31109 Chihuahua, Chihuahua, México (Mexico)
This work presents a study of how the magnetic and temperature variables, as well as the measurement rate, affect magnetic and structural phase transitions for La{sub 0.7}Ca{sub 0.3−x}Sr{sub x}MnO{sub 3} (x=0.15, 0.08, 0.07 and 0.06) manganites. A single phase rhombohedral crystal structure for Sr{sub 0.15} compound and a single phase orthorhombic crystal structure for Sr{sub 0.08}, Sr{sub 0.07}, and Sr{sub 0.06} compounds were identified by X ray diffraction. The Curie temperature adjustment to room temperature was reached for Sr{sub 0.07} sample, in which a Jahn-Teller transition was observed. This Jahn-Teller transition showed a susceptible response to 0.5, 1, 2, 3, 5 and 7 K/min measurement rates, and was revealed without measurement sequence at 234, 257, 196, 233, 245 and 238 K respectively in thermomagnetic curves (10 mT). Also, Curie temperature increases sequentially around 2 K for the same measurement rates. To avoid magnetic field effect, a differential scanning calorimetry for Sr{sub 0.07} sample was obtained in the same temperature region, for 2, 3, 5, 7 K/min showing the Jahn-Teller phase transition at 225 K and a vibrational like behavior in the heat flux below 225 K, for all the temperature rates. The latter, is related to the static to dynamic Jahn-Teller transition. Furthermore, Curie temperature appears around 284 K.
- OSTI ID:
- 22611768
- Journal Information:
- AIP Advances, Vol. 6, Issue 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
- Country of Publication:
- United States
- Language:
- English
Similar Records
Structure-properties phase diagram for La{sub 1-x}Sr{x}MnO{sub 3} (0.1{le}x{le}0.2).
Systematic study of (La sub 1 minus x Gd sub x ) sub 1. 85 Sr sub 0. 15 CuO sub 4 (0 le x le 1): Structure, superconductivity, resistivity, and magnetic properties
Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CALCIUM COMPOUNDS
CALORIMETRY
COUPLING
CRYSTAL STRUCTURE
CRYSTALS
CURIE POINT
HEAT FLUX
JAHN-TELLER EFFECT
LANTHANUM COMPOUNDS
MAGNETIC FIELDS
MANGANATES
ORTHORHOMBIC LATTICES
PHASE TRANSFORMATIONS
SPIN
SPIN-LATTICE RELAXATION
STRONTIUM COMPOUNDS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TRIGONAL LATTICES
X-RAY DIFFRACTION