Magnetic structure and phase diagram of TmB4

Magnetic structure of single crystalline TmB4 has been studied by magnetization, magnetoresistivity and specific heat measurements. A complex phase diagram with different antiferromagnetic (AF) phases was observed below TN1 = 11.7 K. Besides the plateau at half-saturated magnetization (1/2 MS), also plateaus at 1/9, 1/8 and 1/7 of MS were observed as function of applied magnetic field B//c. From additional neutron scattering experiments on TmB4, we suppose that those plateaus arise from a stripe structure which appears to be coherent domain boundaries between AF ordered blocks of 7 or 9 lattice constants. The received results suggest that the frustration among the Tm3+ magnetic ions, which maps to a geometrically frustrated Shastry-Sutherland lattice lead to strong competition between AF and ferromagnetic (FM) order. Thus, stripe structures in intermediate field appear to be the best way to minimize the magnetostatic energy against other magnetic interactions between the Tm ions combined with very strong Ising anisotropy.Comment: 4 pages, 4 figures, conference contribution - CSMAG 0

Large, high quality single-crystals of the new Topological Kondo Insulator, SmB6

SmB6 has recently been predicted to be a Topological Kondo Insulator, the first strongly correlated heavy fermion material to exhibit topological surface states. High quality crystals are necessary to investigate the topological properties of this material. Single crystal growth of the rare earth hexaboride, SmB6, has been carried out by the floating zone technique using a high power xenon arc lamp image furnace. Large, high quality single-crystals are obtained by this technique. The crystals produced by the floating zone technique are free of contamination from flux materials and have been characterised by resistivity and magnetisation measurements. These crystals are ideally suited for the investigation of both the surface and bulk properties of SmB6

Phase Diagram of TmB4 Probed by AC Calorimetry

TmB_4 is a frustrated system based on the Shastry-Sutherland lattice that exhibits complex magnetic properties. In this contribution the magnetic field B vs. temperature T phase diagram of $TmB_4$ has been studied by ultrasensitive AC calorimetry in the temperature range between 2.9 and 12 K and in magnetic fields up to 8 T. Apart from already known phases our measurements have recognized several new phase transitions suggesting that the phase diagram of $TmB_4$ is even more complex and deserves further studies

Transport properties of HoB12

Abstract. We present measurements of the electrical resistivity of single crystalline HoB12 down to a temperature of 1.6 K and in magnetic fields up to 6 T. The obtained results confirm the previous investigation of the magnetic phase diagram by magnetization and specific heat measurements of this compound. The spin wave scattering of conduction electrons and spin disorder resistivity in the antiferromagnetic and in the paramagnetic phase, respectively, are analyzed. Keywords HoB12, electrical resistivity, magnetic phase diagram. PACS 72.15.Eb, 75.50.E

Treatment of T3N0 non-small cell lung cancer with chest wall invasion using stereotactic body radiotherapy

Objectives: Chest wall invasion (CWI) is observed in 5% of localized non-small cell lung cancer (NSCLC). The role of stereotactic body radiotherapy (SBRT) in these patients is unknown. We investigate the safety and efficacy of SBRT in patients with T3N0 NSCLC due to CWI. Methods: Patients with T3N0 NSCLC due to CWI were identified using a prospective registry. CWI was defined as radiographic evidence of soft tissue invasion or bony destruction. We excluded patients with recurrent or metastatic disease. All patients were treated with definitive SBRT. Prescribed dose was 50 Gy in 5 fractions for most patients. Kaplan-Meier analysis was used to estimate survival outcomes. Results: We identified 12 patients treated between 2006 and 2017. Median age was 70 (range, 58–85). Median tumor diameter was 3.0 cm (range, 0.9–7.2). Median survival was 12.0 months (range, 2.4–63). At a median follow-up of 8.9 months (range, 2.1–63), 1-year primary tumor control was 89%, involved lobar control was 89%, local–regional control was 82%, distant control was 91%, and survival was 63%. Of the 4 patients with pre-treatment chest wall pain, 3 reported improvement after SBRT. Two patients reported new grade 1–2 chest wall pain. No grade 3+ toxicity was reported, with 1 patient experiencing grade 1 skin toxicity and 3 patients experiencing grade 1–2 radiation pneumonitis. Conclusions: SBRT for CWI NSCLC is safe, with high early tumor control and low treatment-related toxicity. Most patients with pre-treatment chest wall pain experienced relief after SBRT, with no grade 3+ toxicity observed