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M. Markina

Publications and source records attributed to M. Markina.

3 recordsLinked to original sources

Linear magnetoelastic coupling and magnetic phase diagrams of the buckled-kagom\'{e} antiferromagnet Cu$_3$Bi(SeO$_3$)$_2$O$_2$Cl

Single crystals of Cu$_3$Bi(SeO$_3$)$_2$O$_2$Cl were investigated using high-resolution capacitance dilatometry in magnetic fields up to 15 T. Pronounced magnetoelastic coupling is found upon evolution of long-range antiferromagnetic order at T$_{\mathrm{N}} = 26.4(3)$ K. Gr\"{u}neisen analysis reveals moderate effects of uniaxial pressure on T$_{\mathrm{N}}$, of $1.8(4)$ K/GPa, $-0.62(15)$ K/GPa and $0.33(10)$ K/GPa for $p \parallel a$, $b$, and $c$, respectively. Below 22 K, Gr\"{u}neisen scaling fails which implies the presence of competing interactions. The structural phase transition at T$_{\mathrm{S}} = 120.7(5)$ K is much more sensitive to uniaxial pressure than T$_{\mathrm{N}}$, with strong effects of up to $27(3)$ K/GPa ($p \parallel c$). Magnetostriction and magnetization measurements reveal a linear magnetoelastic coupling for $B\parallel c$ below T$_{\mathrm{N}}$, as well as a mixed phase behavior above the tricritical point around 0.4 T. An analysis of the critical behavior in zero-field points to three-dimensional (3D) Ising-like magnetic ordering. In addition, the magnetic phase diagrams for fields along the main crystalline axes are reported.

cond-mat.str-el

Reply to Comment on "Competition between helimagnetism and commensurate quantum spin correlations in LiCu2O2"

Exchanged interactions in recently observed helical structure in LiCu2O2 is probed by inelastic neutron scattering. The main conlusions of Refs. [1,2] are confirmed: nn interactions in single chains are ferromagnetic and frustrated by nnn antiferromagnetic ones. However, in apparent disagreement with Refs. [1,2] double-chain interactions are found to be of the same order of magnitude as the single-chain ones, and thus involved in the frustration mechanism. [1] Drechsler et al., cond-mat/0411418. [2] A. Gippius et al. Phys. Rev. B 70 (2004), R01426; cond-mat/0312576.

cond-mat.str-el

Helimagnetism in a disordered and geometrically frustrated quantum spin chain

Neutron diffraction and bulk measurements are used to determine the nature of the low-temperature ordered state in LiCu$_2$O$_2$, a $S=1/2$ spin-chain compound with competing interactions. The magnetic structure is found to be helimagnetic, with a propagation vector $(0.5,ζ,0)$, $ζ=0.174$. The nearest-neighbor exchange constant and frustration ratio are estimated to be $J=5.8$ meV and $J_2/J_1=0.29$, respectively. For idealized spin chains these parameter values would signify a gapped spin-liquid ground state. Long-range ordering is attributed to intrinsic non-stoichiometry.

cond-mat.str-el