X-ray study of Nd0.5Sr0.5MnO3 manganite structure above and below the ferromagnetic metal–antiferromagnetic insulator spontaneous phase transition

Abstract

The crystal structure of the manganite Nd0.5Sr0.5MnO3 is studied at temperature T=300 and 77.3 K by means of an x-ray diffractometer. It is shown that the transition from the ferromagnetic metallic state to the antiferromagnetic insulating charge-ordered state is accompanied by a lowering of the symmetry of the structure from orthorhombic to monoclinic. The space-group symmetry of the orthorhombic and monoclinic phases is identified as Imma and P21/m, respectively. Twinning of the crystal and the formation of a twin domain structure with coherent boundaries in the (00l) crystallographic planes are found.

Magnetic phase diagram of Nd0.5Ca0.5−ySryMnO3

“…The analysis of XRD patterns shows that, except for a few minor lines which correspond to Mn 3 O 4 , all major lines can be indexed to an orthorhombic unit cell. The lattice parameters of the compounds with y = 0 and y = 0.5 are consistent with the values reported 10,[12][13][14] in the literature. [10][11][12][13][14] In the XRD patterns of all the compounds with y Ͻ 0.5, we find extra lines corresponding to Pbnm symmetry which are ab- whereas the c lattice parameter increases, initially with y until y ϳ 0.28 and then decreases, as indicated in Fig.…”

Giant magnetic-field changes in radio-frequency absorption in La0.67Sr0.33MnO3 near the Curie temperature

“…The growth rate was 1 mm=h: An additional afterheater was used for lowering the temperature gradients in growing crystal. It is known [11] that manganite crystals produced by the described technique are like single crystals, 1 and, in this respect, they have far better crystal quality and far less porosity than the samples prepared by a solid-state reaction technique. On the other hand, the crystals have twin domain structure.…”

Magnetic phase transitions in the system La1−xBixMnO3+λ

“…These compounds contain ions with orbital degeneracy or Jahn-Teller (JT) ions (in our case Mn 3+ ) [1]. Thus their properties differ appreciably from those of the corresponding substances with the «ordinary» ions: the crystal structure turn out to be distorted, structural phase transitions and transitions in a magnetic subsystem [2][3][4][5][6] are frequently observed in them, and in many cases they have anomalously strong magnetic anisotropy and magnetostriction [7,8]. Such phenomena are connected with an interaction of the JT ions and are called the cooperative Jahn-Teller effect (CJTE).…”