Magnetic phase transitions field-induced

Kadomtseva et al. (2000) measured thermal expansion and longitudinal and transverse magnetostriction in pulsed magnetic fields up to 25 T in Lai - Sr MnOj single crystals (x = 0.1,0.125 and 0.15). The results were ascribed to a suppression of the O phase and field-induced transitions to a new orbital-ordered ferromagnetic state. 

O. Nohadani, S. Wessel, B. Normand, and S. Haas (2004) Universal scaling at field-induced magnetic phase transitions. Phys. Rev. B 69, p. 220402... 

Various types of work in addition to pV work are frequently involved in experimental studies. Research on chemical equilibria for example may involve surfaces or phases at different electric or magnetic potentials [11], We will here look briefly at field-induced transitions, a topic of considerable interest in materials science. Examples are stress-induced formation of piezoelectric phases, electric polarization-induced formation of dielectrica and field-induced order-disorder transitions, such as for environmentally friendly magnetic refrigeration. 

In order to focus on the driving force for phase transitions induced by a magnetic field it is advantageous to use the magnetic flux density as an intensive variable. This can be achieved through what is called a Legendre transform [12], A transformed Helmholtz energy is defined as... 

Sushko YV, Ito H, Ishiguro T, Horiuchi S, Saito G (1993) Magnetic-field-induced transition to resistive phase in superconducting k-(BEDT-TTF)2Cu[N(CN)2]C1. J Phys Soc Jpn 62 3372-3375... 

An exception to the rule that lowering the Iciiiperaiure cutises transitions to phases with increased order sometimes occurs for polar compounds w hich form the smectic l. phase (a layered structure formed by molecular dimers). Decreasing the temperature cutises u transition front nematic to smectic. 1,.,. but a further lowering of the temperature produces J transition back to the nematic phase tcalled the reentrant nematic phase). Electric or magnetic fields also may induce mesomorphic phase transitions. 

In applying a large magnetic field of 0 - 70 Tesla SrCu (60.3)2 crosses over into new quantum phases observable as distinct plateaus in the magnetization [21-23], These plateaus correspond to 1/8,1/4 and 1/3 of the saturation magnetization of the spin system [24—26] and are understood as field induced triplet states that are divided in a commensurate way on the dimer lattice. Recent NMR experiments on the 1/8 plateau at 28 Tesla and at very low temperatures (35 mK) show a transition-like crystallization of triplets within a larger supercell and Friedel-like oscillations of the field induced spin polarization [27],... 

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