Title :
Giant volume magnetostriction at room temperature and its connection with colossal magnetoresistance in La0.7Ba0.3MnO3
Author :
Demin, R.V. ; Koroleva, L.I. ; Mukovskii, Ya.M.
Author_Institution :
Lomonosov (M.V.) State Univ., Moscow, Russia
Abstract :
In this research, the giant volume magnetostriction ω near Curie point TC in La0.7Ba0.3MnO3 single crystal is investigated. The thermal expansion Δl/l, magnetostriction λ, electrical resistivity ρ, and magnetoresistance Δρ/ρ of the single crystal are also studied. Results show that ω is negative and its magnitude reaches a maximum near TC = 310 K. Further heating makes |ω| vanish rapidly. A maximum value of |ω| ≈ 4 × 10-4 at H = 8.2 kOe is obtained and at room temperature, |ω| = 2.54 × 10-4. The ρ(T) dependence is also found to have a maximum near TC and metallic type of conductance at TC. |Δρ/ρ| is found to be 22.7% at maximum field of 8.2 kOe. At TC Δl/l linearly increases with T which is caused by the phonon anharmonic contribution. The slope of Δl/l is considerably extended in TC-region that is connected with an extra contribution in thermal expansion due to the magnetic two-phase state destruction.
Keywords :
Curie temperature; barium compounds; colossal magnetoresistance; electrical conductivity; heat treatment; lanthanum compounds; magnetostriction; phonons; thermal expansion; 293 to 298 K; Curie point; La0.7Ba0.3MnO3; colossal magnetoresistance; electrical resistivity; giant volume magnetostriction; heating; magnetic two-phase state destruction; metallic conductance; phonon anharmonic contribution; room temperature; single crystal; thermal expansion; Antiferromagnetic materials; Charge carriers; Colossal magnetoresistance; Giant magnetoresistance; Insulation; Magnetic fields; Magnetosphere; Magnetostriction; Tail; Temperature;
Conference_Titel :
Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International
Print_ISBN :
0-7803-9009-1
DOI :
10.1109/INTMAG.2005.1464402
