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Journal of Rare Earths 2022年第7期40卷 1106-1117页

作者： Lei Huang Lichun Cheng shunkang pan Qingrong Yao Qianxin Long Man Wang Yucheng Chen Huaiying Zhou School of Materials Science and Engineering Guilin University of Electronic TechnologyGuilin 541004China Guangxi Key Laboratory of Information Materials Guilin University of Electronic TechnologyGuilin 541004China

In this paper,the effect of Ba^(2+)ions A-site doping LaFeO_(3)on structure,magnetic properties and microwave absorption properties was investigated by the sol-gel method.According to the TEM and FullProf refinement results,the structure of LaFeO_(3)changes from orthogonal(SG:Pnma)to cubic(SG:Pm-3 m)when the Ba doping amount is x=0.4.The SEM image shows that the particles size tends to decrease with the increase of Ba content.The production of weak ferromagnetism indicates that Ba doping has a significant effect on the magnetic properties of LaFeO_(3).The Neel temperature(TN)decreases significantly with the increase of Ba doping amount.An appropriate amount of Ba doping can effectively increase the dielectric and magnetic loss of LaFeO_(3)ceramics powders.The increase permittivity(ε’andε″)may be attributed to the hopping of the electrons between the Fe^(3+)and Fe^(4+)ions with the Ba^(2+)ions doping.The minimum reflection loss(RL_(min))of La_(0.9)Ba_(0.1)FeO_(3)at 6.72 GHz reaches-30.04 dB,its effective bandwidth(RL≤-10 dB)is 2.1 GHz,and the matching thickness is only 3.2 mm.These results indicate that Ba doping can effectively control the microwave absorption properties of LaFeO_(3),especially in the Cband.

关键词： LaFeO_(3)ceramics Crystal structure Magnetic Electromagnetic parameters Microwave absorption Rare earths

Magnetic and microwave absorbing properties of Ce-Co-based alloy powders driven with lanthanum content

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Journal of Rare Earths 2020年第7期38卷 749-754,I0003页

作者： Yu He shunkang pan Jingjing Yu School of Material Science and Engineering Guilin University of Electronic TechnologyGuilin 541004China

The composites of Ce-Co-based alloys doped with La content were fabricated via a vacuum arc melting method.The influences of La addition on microstructure,electromagnetic parameters,magnetic property and microwave absorbing property were measured by the corresponding equipment.The morphology characteristics manifest that all samples display sheet structure,and the average particle size of alloy powders increases with increasing La content The saturation magnetization(MS) decreases with increasing La addition as a whole.The minimum reflection loss(RL) of La0.4Ce1.6Co17 alloy powder about-42.29 dB can be obtained about-42.29 dB at 7.84 GHz with the matching thickness of 1.8 mm,and the corresponding effective bandwidth can achieve about 2.24 GHz.In addition,the minimum RL frequency moves towards a lower frequency region as the La content increases.The minimum RL of La0.3Ce1.7Co17alloy powder is less than-20 dB ranging from 1.2 to 2.4 mm in the whole 4-16 GHz.The maximum bandwidth can reach about 4.88 GHz at the given thickness of 1.2 mm.In general,these all indicate that the La addition is beneficial to improving the microwave absorbing performance in both effective bandwidth and absorption intensity.

关键词： Ce-Co-Based alloys Magnetic property Microwave absorbing property Reflection loss Rare earths

Electromagnetic and microwave absorption properties of Er-Ho-Fe alloys

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Journal of Rare Earths 2018年第7期36卷 715-720页

作者： Jialiang Luo shunkang pan Lichun Cheng Peihao Lin Yu He Junqing Chang School of Materials Science and Engineering Guilin University of Electronic Technology Guangxi Key Laboratory of Information Materials Guilin University of Electronic Technology School of Materials Science and Engineering Central South University

The ErxHo（2-x）Fe（17）（x = 0.0, 0.1,0.2, 0.3, 0.4） powders were prepared by arc melting and high energy ball milling method. The influence of the Er substitution on phase structure, morphology, saturation magnetization,electromagnetic parameters was investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）, vibrating sample magnetometer（VSM） and vector network analyzer（VNA）,respectively. The results show that the saturation magnetization increases and the average particle size increases with the increase of Er content. The minimum absorption peak frequency shifts towards a lower frequency region with the increase of Er content. The ErxHo2-xFe17 powder can achieve the minimum RL of-24.07 dB at 6.96 GHz with a thickness of 2.0 mm and the minimum RL is less than-20 dB at the thickness range from 2.0 to 3.0 mm. The minimum RL of ErxHo2-xFe17 is-37.26 dB at5.68 GHz and the frequency bandwidth of R〈-10 dB reaches about 1.2 GHz with a thickness of 2.4 mm.And the microwave absorbing properties of the composite with different weight ratios of Er0.3Ho1.7Fe17/graphene were researched. The microwave absorbing peaks of the composite shift to lower frequency with the increase of graphene content. The values of the minimum RL of ErxHo2-xFe17/graphene are close to-10 dB with absorbing coating thicknesses increased.

关键词： ErxHo2-xFe17 alloys Reflection loss Electromagnetic parameters Magnetic properties Microwave absorbing properties Rare earths

Microwave Absorbing Performance of RE-Fe Based Alloys

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Journal of Wuhan University of Technology(Materials Science) 2015年第3期30卷 607-610页

作者：刘星 pan shunkang CHENG Lichun 饶光辉 LIN Peihao Guangxi Key Laboratory of Information Materials Guilin University of Electronic Science and Technology

REI3Fes4Cr3（RE=Ce, Pr, Tb, Er） and Pr13_XFes4Cr3Ti（x=0, 2, 4, 6） alloy powders were prepared by are smelting method and high energy ball milling technique. The phase structure and the morphology of the alloy powders were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, and their microwave absorbing properties were determined by a vector network analyzer. The results show that the alloys with light rare earths （Ce, Pr） have good low frequency absorbing property and those with heavy rare earths （Tb, Er） exhibit an improved high frequency absorbing property. The minimum refleetivity at the absorbing peak frequency of RE,FeuCr3（RE=Ce, Pr, Tb, Er） are -9.49 dB at 5.76 GHz, -22.38 dB at 7.92 GHz, -18.52 dB at 11.68 GHz and -17.59 dB at 10.24 GHz, respectively. The absorbing bandwidth under -10 dB of the Pr13FesaCr3 powder was widened from 1.91 GI-Iz to 3.89 GHz by adding 2% Ti, but the reflectivity of the alloy was increased from -22.38 dB to -14.91 riB.

关键词： RE-Fe based alloys microwave absorbing property reflectivity electromagneticparameter high energy ball milling

盾构下穿既有矩形箱涵变形规律及开裂因素研究

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土工基础 2023年第4期37卷 629-634页

作者：付顺康潘大荣重庆交通大学重庆400074 南京工程学院南京211167

盾构下穿时因各种施工影响会导致既有箱涵变形过大进而引起开裂。为分析盾构下穿时既有箱涵的变形规律及其与裂缝产生的相互关系,以常州2号线某标段为背景,采用有限元法对盾构下穿既有矩形箱涵全过程进行模拟,结合现场监测数据与箱涵开... 详细信息

盾构下穿时因各种施工影响会导致既有箱涵变形过大进而引起开裂。为分析盾构下穿时既有箱涵的变形规律及其与裂缝产生的相互关系,以常州2号线某标段为背景,采用有限元法对盾构下穿既有矩形箱涵全过程进行模拟,结合现场监测数据与箱涵开裂情况,并考虑注浆量、土仓压力、摩擦力等施工参数对变形与开裂的影响。结果表明:随着盾构隧道开挖,既有箱涵处于偏压状态,进而导致箱涵产生差异性沉降并向掘进方向位移,而裂缝的出现与第一主应力应力集中相关,由掘进方向位移与沉降二者控制;二次注浆对竖向位移影响最大,随着二次注浆范围的增大,竖向沉降可减少84.3%,摩擦力其掘进方向位移影响最大,随着摩擦力的增加,掘进方向位移可增大55%,土仓压力的增加会降低其竖向位移而增大掘进方向位移。

关键词：盾构近距离施工矩形箱涵变形开裂数值模拟

Effect of rare earths on microwave absorbing properties of RE-Co alloys

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Journal of Rare Earths 2015年第3期33卷 271-276页

作者：何崇康潘顺康成丽春刘星吴亚军 School of Materials Science and Engineering Guilin University of Electronic Technology Hezhou Science and Technology Bureau School of Materials Science and Engineering Central South University

The powders of RE2Co17（RE=Y, Ce, Nd, Ho, Er） and Ho x Co100–x（x=6, 8, 10, 12） alloys were prepared by the arc melting method and high-energy ball mill process. The compositions and morphologies of the alloys were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）, and the microwave absorbing properties were studied by a vector network analyzer. The results showed that the alloy of Y2Co17 had better absorbing properties at low frequencies and its lowest reflectivity value was –9.5 d B at 3.8 GHz. The lowest reflectivity value of Ho2Co17 alloy was –13.7 d B at 7.02 GHz and it obtained large absorbing bandwidth. Reflectivity value less than –5 d B was from 5.1 to 10.2 GHz. When x=6 and x=8, the alloys of Ho x Co100–x consisted of Ho2Co17 phase and Co phase. They had good radar absorbing properties. With increase in Ho content, the minimum reflectivity value worsened and the absorbing peak frequency shifted toward higher frequencies. But when x=12, the absorbing peak frequency shifted toward lower frequencies but the minimum reflectivity value worsened.

关键词： RE2Co17 alloy microwave absorbing properties high energy ball milling Ho content rare earths

Effects of cobalt substitution on structure and microwave absorption properties of PrNi_5 alloy

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Journal of Rare Earths 2015年第12期33卷 1324-1328页

作者：潘顺康熊吉磊成丽春姚青荣饶光辉 School of Material Science and Engineering Guilin University of Electronic Technology Guangxi Key Laboratory of Information Materials Guilin University of Electronic Technology School of Materials Science and Engineering Central South University

The polycrystalline samples PrNi5_xCox （x=0.0, 0.1, 0.2, 0.3, 0.4） were synthesized by arc smelting and high energy ball milling method. The phase structure, morphology, saturation magnetization and electromagnetic parameters of the alloy powders were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, vibrating sample magnetomctry （VSM） and vector network analyzer （VNA）, respectively. The results revealed that the lattice parameter a and c and unit-cell volume V increased with the increasing amount of Co substitution. The saturation magnetization increased as Co content increased. The minimum absorp- tion peak frequency shifted towards lower frequency region with the increasing amount of Co substitution. And the minimum reflec- tion loss of the PrNi5 xCox powders increased first and then decreased with the increasing amount of Co substitution. The PrNisCox alloys possessed the excellent microwave absorbing properties. The minimum reflection loss of the PrNi4.gCo0,1 alloy all could reach 20.0 all3 with the coating thickness ranging from 1.8 to 3 ram. The minimum reflection loss of PrNi4.gCoo.l powders was -36.20 d13 at 7.76 GHz, and the frequency bandwidth ofR〈10 dB reached about 1.50 GHz with the best matching condition d=2.0 ram.

关键词： PrNi5 alloy Co substitution structure electromagnetic parameters microwave absorbing properties rare earths

Crystal structure and magnetic behavior of the La_(0.1)Bi_(0.9)FeO_3 compound

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Journal of Rare Earths 2016年第4期34卷 396-400页

作者：姚青荣沈逸豪周怀营饶光辉邓健秋潘顺康 School of Materials Science and Engineering Central South University School of Materials Science and Engineering Guilin University of Electronic Technology Guangxi Key Laboratory of Information Materials Guilin University of Electronic Technology

The nano-crystalline La_（0.1）Bi_（0.9）FeO_3 compound was successfully synthesized by starch-based combustion method. The crystal structure and magnetic behavior were studied by temperature-dependent X-ray diffraction（XRD）, scanning electron microscopy（SEM）, differential scanning calorimetry（DSC） and magnetic measurements. The La_（0.1）Bi_（0.9）FeO_3 compounds crystallized in a rhombohedrally distorted perovskite structure with space group R3 c. The substitution of La for Bi reduced the rhombohedral distortion. The structural phase transitions in La_（0.1）Bi_（0.9）FeO_3 driven by temperature showed that the extraordinary two-phase coexistence state of BiF eO 3 and LaF eO 3 was observed in a narrow temperature range of 630–700 oC. The magnetization of the La_（0.1）Bi_（0.9）FeO_3 sample was improved by heat treatment in the temperature range. When the heat treatment temperatures rose from 25 to 600 oC, the remanence（Mr） and coercivity（Hc） of the La_（0.1）Bi_（0.9）FeO_3 compound almost remained the same, and increased rapidly to 0.134 emu/g and 7.1 KOe on further increasing the heat treatment temperature to 650 oC.

关键词： X-ray diffraction phase transition La-doped BiFeO3 magnetism rare earths

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Si含量对NdFe材料微波吸收特性的影响

稀有金属材料与工程 2012年第4期41卷 645-648页

作者：林培豪杨涛潘顺康王磊桂林电子科技大学广西桂林541004

采用高能球磨和晶化热处理方法制备钕铁吸波粉体,研究Si含量对钕铁粉体吸波性能的影响。结果发现:在高能球磨和微氧化气氛下进行700℃,1h晶化处理后,Nd8Fe92、Nd8Fe89Si3和Nd8Fe87S5粉体组织均由α-Fe、Nd2O3和Fe17Nd2相组成,加入Si后,... 详细信息

采用高能球磨和晶化热处理方法制备钕铁吸波粉体,研究Si含量对钕铁粉体吸波性能的影响。结果发现:在高能球磨和微氧化气氛下进行700℃,1h晶化处理后,Nd8Fe92、Nd8Fe89Si3和Nd8Fe87S5粉体组织均由α-Fe、Nd2O3和Fe17Nd2相组成,加入Si后,粉体的Fe17Nd2相对量增加;Nd8Fe92粉体的反射率最小值约为-4.5dB,吸收峰频率约为4.4GHz,加入Si后,粉体的反射率最小值降低,吸收峰频率升高,吸波带宽变宽;Nd8Fe92粉体以介电损耗为主,Nd8Fe89Si3和Nd8Fe87Si5粉体以磁损耗为主。

关键词：钕铁合金高能球磨吸波性能热处理

Preparation and microwave absorption properties of NdFeB alloys

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Journal of Rare Earths 2015年第5期33卷 514-518页

作者：熊吉磊潘顺康成丽春刘星林培豪姚青荣 School of Material Science and Engineering Guilin University of Electronic Technology School of Materials Science and Engi-neering Central South University College of Chemistry and Life Sciences Hezhou University

In order to improve the microwave absorbing properties of NdFeB alloys, as-jet milled powders were further processed in a planetary mill. The phase structure, morphology and particle size of the alloy powders were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and laser diffraction-based particle size analyzer, respectively. The saturation magnetization and electromagnetic parameters of the powders were determined by a vibrating sample magnetometer （VSM） and a vector network ana-lyzer （VNA）, respectively. The results showed that the saturation magnetization decreased as the milling time increased. The mini-mum absorption peak frequency shifted towards the lower region and the reflection loss values increased with increasing the ball mill-ing time. The minimum absorption peak value of the powders milled for 15 h on the basis of jet milling reached–44.4 dB at 11.04 GHz, and the bandwidth of R〈–10 dB was 1.2 GHz with the best matching thickness of 1.8 mm.

关键词： jet milling ball milling NdFeB alloys magnetic properties microwave absorbing properties rare earths