TY - JOUR AU - Bykov, Maxim AU - Zhang, Jian AU - Schönleber, Andreas AU - Wölfel, Alexander AU - Ali, Sk Imran AU - van Smaalen, Sander AU - Glaum, R. AU - Koo, H.-J. AU - Whangbo, M.-H. AU - Reuvekamp, P. G. AU - Law, J. M. AU - Hoch, C. AU - Kremer, R. K. TI - Spin-Peierls distortions in TiPO<sub>4</sub> JO - Physical review / B VL - 88 IS - 18 SN - 1098-0121 CY - College Park, Md. PB - APS M1 - DESY-2014-01098 SP - 184420 PY - 2013 AB - On the basis of single-crystal x-ray diffraction we show that TiPO4 undergoes a spin-Peierls distortion below 74.5(5) K, with a dimerization of the Ti chains along the c axis. Between 74.5(5) and 111.6(3) K, TiPO4 develops an incommensurate (IC) phase with temperature-dependent q vector (σ1,0,0). Density functional calculations strongly suggest that the IC phase results from a frustration of the lock-in spin-Peierls transition due to the competition of three energetically almost degenerate crystal structures and elastic coupling of the Ti chains via the bridging PO4 units. The phase transition into the IC phase is of second order, but the lock-in transition into the spin-Peierls distortion below 74.5 K is of weak first order in nature. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000327154300006 DO - DOI:10.1103/PhysRevB.88.184420 UR - https://bib-pubdb1.desy.de/record/166168 ER -